Executive Summary
Margincompressionoccursatvarioustimesduringthematuringstagesofmost industries.Atitscore,margincompressionissimplyareductionofoperating margins(grossrevenuelessthecostofgoodssold)andiscausedbyavarietyof factors,bothinternalandexternal,microandmacro. Thepaymentprocessingindustryisnoexception,andhasnotbeenimmune fromrecentmargincompression.Overthepastfewyears,manyIndependent SalesOrganizations(ISOs)haveexperiencedsignificantreductionsinmarginon bothdirectprocessingrevenuesandPOShardwaresales. Thecausesofmargincompressioninthepaymentprocessingindustryarevaried andcomplexandinclude:increasedcompetition;poorsalesforcetrainingand practices;inflatedmerchantportfoliovaluations;freeterminalplacements;and changesineconomicconditions. Thispaperdefinesmargincompressioninthepaymentprocessingindustry (specificallywithregardtoISOs),examinessomecausesofmargincompression andmakesrecommendationsforpreventing,mitigatingandreversingthetrend. Margincompressionforamaturingindustrymaybepredictable,butforthe savvyandattentiveISO,itcanbehighlycontrollable.Margin Compression in the Payment Processing Industry
For the typical ISO, revenues come
primarily from one or both of two general
and broadly defined sources: processing
revenues and POS hardware sales. For a
typical, mature ISO, the overwhelming
majority of revenues will be derived from
processing fees with little revenue derived
from hardware sales. Obvious exceptions
include ISOs with specific POS hardware
or system sales strategies.
Historically, new ISOs generated the
majority of their early revenues from
hardware sales while building a portfolio
to generate increased, business‐sustaining
processing revenues.
In this paper, processing revenues
generally refer to the operating profit
generated by the gross revenue paid to
the ISO by their acquiring bank or
processor, after cost of goods sold
(interchange, authorization and
settlement fees, etc.) and before costs
(salaries, overhead, sales expense, etc.).
Hardware revenue generally refers to the
net margin derived by the gross selling
price less the wholesale price of the item
sold. Processing revenue is expressed as a
percentage of processed volume. For
example, a merchant processing $10,000
in card volume generating $100 in
processing revenue provides 1% (or 100
basis points) of margin.
Origins of Margin Compression
In the early development stages of the
electronic payment processing industry,
few merchants had POS devices.
Therefore, the primary goal of ISOs was
hardware deployment (POS terminals and
printers, electronic cash registers, etc.).
Many early stage ISOs enjoyed hardware
margins in excess of 100% with leasing as
a popular option for the small and mid‐
sized merchants.
As deployment saturation began to
develop and compress hardware margins,
a second generation of hardware models –
along with the rapid adoption of PIN
debit – provided renewed deployment
opportunities with ISOs still enjoying
margins as high as 50% or more.
During this timeframe, merchant demand
for hardware grew as they sought to
transition from paper to electronic
capture. Additionally, integrated
terminals supporting PIN debit
transactions and, to a lesser extent, check
processing provided easy merchant
processing account opportunities to ISOs.
The fertile landscape provided ISOs with
strong processing margins – in many
cases exceeding 100 basis points on
processed volume. It is also important to
note that, during the industry’s early
stages, processing volume was a small
fraction of current volumes and
represented a small share of a merchant’s
payment acceptance mix.
Industry resource, The Nilson Report,
noted in its October 2009 issue that, while
processing volume has increased in the
last decade, merchant’s fees as a
percentage of processing volume have
actually declined from a peak in 2005.
purchases have impacted fees, but margin
compression has also had a demonstrable
impact.
Source: Nilson Report, October 2009
As the payment processing industry
matured, it attracted more competition
from a variety of sources: entrepreneurial
startups, banks, large cross‐marketing
programs and others. With new hardware
deployment opportunities becoming
limited to new business start ups and
additional locations, less‐frequent
upgrades and replacements, ISOs were
forced to begin to focus primarily on their
processing service offerings, which
naturally lead to a focus on price.
During this same timeframe, several ISOs
and processors went public, attracting
both institutional and private capital into
the industry, which significantly
increased both company and portfolio
valuations. The increased value placed on
each processing account allowed many
ISOs to invest far more heavily in
merchant acquisition. This, in turn, led
many ISOs to offer free hardware to
merchants as an incentive to sign up with
them, causing the virtual elimination of
hardware margins ISOs experience today.
General Causes of Margin Compression
The causes of margin compression are
extremely complex and varied. Though
margin compression is typical in most
industries as they mature, the payment
processing industry has experienced
recent margin compression due to a
variety of somewhat interrelated factors. 1. Economic Conditions – Internal
A significant byproduct of the
maturation of the payment processing
industry has been the exponential
growth of same store electronic
payment acceptance and a widening
of acceptance locations. During the
past decade, more and more non‐
traditional acceptors have come to the
market. In addition, card volume as a
percentage of overall sales mix has
continued to grow. It has been
common for certain business segments
to see double digit growth of card
volume while overall sales have
remained flat.
Like most businesses, ISOs have both
fixed and variable costs. With the
ever‐increasing volume per account,
many ISOs have been able to reduce
sometimes expanding revenue per
processing account.
Furthermore, the predominance of
three‐tiered pricing (i.e. qualified,
mid‐qualified, non‐qualified)
combined with a decoupling of
interchange rates for credit and debit
products by the card associations
(Visa, MasterCard, Discover) and ever
increasing “less than qualified”
transactions (reward, corporate, etc.)
has allowed ISOs to maintain or even
lower “qualified” rates while still
enjoying constant and sometimes
increased processing margins.
However, in recent years ISOs have
begun offering more small to mid‐
sized businesses “pass‐through”
pricing which typically generates a
lower, fixed margin and eliminates
margin inflation caused by debit
interchange differentials and higher
rates for less than qualified
transactions. Traditionally, a pass
through pricing model was used for
very large processor based merchants.
As greater transparency is created by
Visa and Mastercard for their
wholesale interchange rates, further
pressure to adopt pass through pricing
may increase.
2. Economic Conditions – External
The broad, country‐wide economic
decline has caused more merchants to
closely examine supplier costs,
including costs of payment processing.
More and more merchants have
contacted their providers for “rate
reviews” and merchants are far more
receptive to low‐rate offers from ISOs
and agents. This has led to three
observable results: one, some ISOs
have chosen to reduce margins to
retain existing accounts. Two,
merchants are far more likely to leave
their incumbent provider for lower
rate offers. Three, some merchants
have chosen to stop accepting
payment cards altogether.
3. Retailer Industry Push Back– Government Regulation
Over the past decade, merchants have
become more vocal as an industry in
raising awareness of the fees that they
pay to support the acceptance of
payment cards. While deep debates
have been had on the very tangible
benefits that merchants receive
through acceptance, such as increased
sales, low charge‐off rates vs. in house
credit programs and customer
convenience / satisfaction; merchants
have raised fee arguments to a fever
pitch thereby placing additional
pressure in their community to drive
down rates as an industry. As a result
of retail industry lobbying,
government regulation and oversight
have been proposed in the past several
years and has made its way in the
form of governmental study into
recent legislation.
4. Increased Competition/Lack of Tangible “Offer”
In recent years, the payment
processing industry has seen a
significant increase in competition,
partially as a result of extremely low
barriers to entry. In addition to
competition created by new ISOs, the
industry now includes competition
from companies such as Google,
PayPal, Intuit (QuickBooks), Sam’s
Club, Costco, UPS, etc. Further, new
and existing ISOs have continually
expanded their sales operations and
call centers. It is estimated that the
average merchant receives dozens of
merchant account solicitations each
month. As the “supply” has increased
faster than the “demand,” margins
have decreased. Years ago, opening a
merchant account was a difficult and
hard to source service. Today, due to
the competition (and the internet!), it
is almost as simple and accessible as
opening a new checking account.
During this time of expanded
competition, fewer tangible sales
opportunities exist. There have been
no recent POS developments to drive
equipment upgrades (the most recent
– contactless – has still not managed to
leave the starting gate in the small to
mid‐sized market) since PIN pad
deployments almost a decade ago.
Further, with the overwhelming
majority of all payments processed
through one of only a handful of
processors (First Data, Paymentech,
Elavon, TSYS, Global), and the
ubiquity of POS terminal design and
functionality, there is little to no brand
differentiation available as a sales tool.
In most ways, payment processing
services have become commoditized,
further leading to margin
compression.
In the classic marketing triangle – of
service, product, price – price is
generally the easiest to compete on,
especially in the short‐term and in
light of the above.
According to analysis of nearly 90
merchant portfolios during the 2003 –
2007 timeframe by industry
participant, Calpian, monthly
revenues per merchant has declined in
most merchant segments. The most
concerning component of the analysis
is that through margin compression,
new merchants being sold by ISOs are
at lower margins than the tenured and
attriting merchants they are replacing
in the ISO’s portfolio. In essence,
some ISOs may be engaging in a
“sprint to the bottom of margins.”
Merchant Portfolios By Average Revenues (% of Total Portfolios) 0 10 20 30 40 50 60 <$20 $20-$40 >$40 Monthly Revenue Per Merchant (Avg)
% o f P o rtfo li o s 2003-2006 2006-2007
Merchant Portfolios By Average Revenues (% of Total Portfolios) 0 10 20 30 40 50 60 <$20 $20-$40 >$40 Monthly Revenue Per Merchant (Avg)
% o f P o rtfo li o s 2003-2006 2006-2007
Sample Size # Portfolios
2003-2006 51 2006-2007 38 Total 89 Source: Calpain
5. Poor Sales Representative Training
Partially as a result of all of the
previous points and the resulting
margin compression, many ISOs have
attempted to grow their internal and
external sales staff as quickly and
efficiently as possible. Proper sales
representative training is a significant
cost, especially in a complex industry
such as payment processing, in which
the learning curve is long and steep.
In many cases, ISOs attempt to utilize
contract sales staff, with inherently
high turnover rates, which further
decreases the ROI of sufficient and
significant training programs. And
often trainers have not been fully and
properly trained themselves, adding
to the problems of untrained sales
staff. With lack of proper training,
and misrepresentation (both
intentional and unintentional), ISOs
often revert to competing on the
easiest attribute to copy, low price
offers, furthering the industry’s
margin compression.
6. Increased Competition for
Agents/Agent Awareness
ISOs employing a typical
agent/contractor model face increased
competition for qualified experienced
agents. Over the past decade,
increased access to information
provided by the internet, the
Electronic Transaction Association’s Transaction Trends magazine, The Green
Sheet and other publications have
created a far more informed agent
population.
Further, what was once a “home‐
grown” small industry now has a
myriad of advertising and marketing
outlets to attract experienced sales
reps. During the early days of the
“agent model,” ISOs relied on
recruiting new agents from outside the
payment processing industry. Today,
a majority of the recruitment comes
from within. All of this new agent
marketing has created in essence
bidding wars for agents with one ISO
after another offering higher and
higher agent compensation.
In 1998, top agents could expect to
receive 30‐50% of the overall
processing revenue. Today, 75% or
more is available to agents. Some ISOs
even advertise up to 100% residual
The increased agent competition and
significantly increased compensation
to agents with no offsetting cost
reductions for ISOs have created
significant ISO net margin
compression.
Preventing and Mitigating Margin Compression
While margin compression is traditionally
present in most mature industries such as
payment processing, there are many
strategies that an ISO can implement to
help prevent or mitigate margin
compression. These strategies can broadly
be categorized into two approaches:
customer‐focused and internally‐focused.
Merchant Focused Strategies
Margins can be preserved and often
expanded if ISOs change their focus.
These changes can include:
Identifying new acceptors to find
merchants that your competition has
not
Solving merchant problems and
selling value
Formalizing and focusing on merchant
retention
Identifying New Acceptors
Typical “Main Street” merchants receive
dozens of payment processing
solicitations each month – by phone, in
person and by direct mail – making it
very difficult to engage these merchants
in meaningful conversation leading to a
sales presentation.
Rather than participating in the “herd”
mentality, focus on bringing products and
services to new and historically under‐
solicited market segments. With this
approach, ISOs will often avoid having to
displace an incumbent processor,
eliminating the need to use the tired
“better price” sales pitch which only leads
to reduced overall margins.
Major card brands have been very
successful in penetrating many markets
for payment card acceptance. As an
example, over 10 years ago, it was still the
exception for grocery stores or quick
service restaurants to accept payment
cards. However, despite the efforts of the
major card brands to penetrate every
conceivable market, acceptance is still not
universal by all merchants in all
commerce situations. Acceptance
opportunities exist in many market
segments, including business to business
payments; mobile commerce, such as
home delivery services; micro‐payments,
such as vending machines; and recurring
payments, such as utility, insurance and
property management.
Additionally, first‐time card acceptance
opportunities also exist within various
ethnic, immigrant and first‐generation
businesses in many locales. Many of these
businesses traditionally conduct
commerce in cash and sometimes store
credit, with card acceptance being a
acceptance mix. Proper networking
within these business segments can yield
a solid referral source.
Finally, there is renewed activity in the
new business segment. Traditionally,
economic disruptions and increased
unemployment have lead to an increase in
new business creation. The current
recession is no exception. According to
the 2009 release of Kauffman Index of
Entrepreneurial Activity report, a leading
indicator of new business creation in the
United States, over 6 million new
businesses were created in the United
States in 2008 (source:
http://www.kauffman.org/research‐and‐ policy/kauffman‐index‐of‐
entrepreneurial‐activity‐1996‐2008.aspx).
Since unemployment increased in 2009
and continues to be high in 2010, it is
likely that the pace of new business
creation will continue. Identifying and
targeting new businesses can offer ample
new merchant opportunities as many
ISOs have been very successful
contracting with startup businesses.
Solve Merchant Problems and Stop Selling on Price Alone
After identifying your target prospects,
how do you position your product
relative to the competition? Is price your
primary differentiator? If so, you are
creating internal margin compression.
Unless you are achieving significant
scale and continually improving internal
efficiencies, this strategy will negatively
impact your bottom line.
While price is important, value is a far
more important factor to all consumers,
and prospective merchants are no
exception. Consumers routinely pay $4
for a cup of premium coffee when a $1
cup is readily available. Car buyers
shun “cheap” in favor of value and
quality (remember the Yugo?).
Merchant principals are consumers, and
value is a key attribute in their decision‐
making process.
Offering nothing more than a low price
devalues your service and opens the
door to any and every competitor
offering what appears to be a lower
price.
ISOs can easily present value over price
by simply identifying the merchant’s
needs. While pain points vary from
prospect to prospect, all merchant
prospects will have specific hot buttons.
Asking probing questions (such as
“What do you like about your current
provider?” and “What don’t you like
about your current provider?”) will help
uncover their hot buttons and will help
lead to a higher‐margin sale.
Perhaps the prospect has reconciliation
issues due to daily discount, or a hard to
read statement? Can they benefit from
an electronic gift and loyalty card
program? Can a check processing
solution benefit them?
By asking the proper questions, you will
not only lead yourself to the sale, you
will become a solutions consultant to
the prospect, instead of just an “I can
save you money” offer.
Merchant Retention
Keeping your existing merchant
relationships will protect processing
margins and revenues. Maintaining your
existing merchants will allow you to focus
on increasing your portfolio base, instead
of replacing attriting merchants – often at
reduced margins.
While there are many strategies ISOs may
employ to reduce attrition, a full
understanding of your portfolio makeup
is needed. Merchants can be analyzed and
retention efforts organized by the
following factors:
1. Customer Profitability
Understanding the actual, real value
of your merchant accounts is vital to
allow retention efforts to be
concentrated on the most profitable
and important accounts. This process
for identifying your customers can be
simple to complex. For a starting
point, you will need to determine the
margin per customer (billings to
customers less cost of goods sold).
Once you have margin established,
you then need to understand all
internal costs incurred in selling,
boarding and servicing the merchant.
Sometimes these costs can be uniquely
identified down to a specific
merchant, such as how often the
merchant calls in for servicing or if
free supplies are provided to a specific
merchant. Other times, the ISO will
find that costs need to be assessed to
merchants on an allocation basis (total
costs / divided by number of
merchants) for expenses such as rent
and furniture. In determining
profitability, an ISO may want to
acknowledge and put a financial
number to extra benefits a merchant
provides them such as referrals or
testimonials.
Once real profitability is determined,
merchant accounts should be ranked
or classified into profit groups such as
“very profitable,” “moderately
profitable,” “marginally profitable,”
and “not profitable.” You might be
surprised to discover that accounts
previously considered “moderately
profitable” have diminished to “not
profitable.”
By stratifying merchant accounts in
this manner, retention efforts can be
more efficiently focused. Keeping
larger, more profitable accounts
obviously requires more effort than
keeping smaller accounts. Further,
servicing resources (proactive
visits/calls, priority call routing, free
supplies, etc.) can be dedicated more
efficiently to provide the greater
service to the most profitable accounts.
And retention efforts can be easily
tracked and refined based upon
success in each group.
An additional goal of this strategy is to
place an emphasis on promoting
merchants from a particular group
into the next level up. By pricing
changes and additional service
offerings, unprofitable merchants can
be upgraded to marginally profitable,
and marginally profitable merchants
can be upgraded to moderately
nothing if you lose a marginally or
unprofitable merchant due to a price
increase.
2. Attrition Analysis
Another important foundational
element in retaining merchant
accounts is to understand and track
reasons merchants leave you. Attrition
should be tracked by profitability
group, market segment both MCC
and type (such as retail, MOTO, etc.)
and attrition reason. ISOs should
analyze their attrition data to identify
patterns within the overall portfolio or
specific niche groups that might
indicate products, service or pricing
that needs to be addressed or
improved.
The greater the details, such as the
types of merchant accounts, average
age of account, and attrition reasons,
the more valuable and actionable the
data will be in understanding why
merchants are leaving and developing
strategies to reduce this attrition. For
example, are merchants leaving
during the initial year of processing?
Maybe their sales personnel are over‐
promising or otherwise misleading
merchants. Are more tenured
merchants leaving? Maybe they feel
forgotten or unappreciated as
customers and they require more
lifetime customer interaction to
continually show value.
The attrition analysis should also
reveal common attributes within the
merchant accounts retained. Is there a
common baseline of services offered to
these accounts? Do the merchants
share common demographic attributes
(i.e. MCC, processing methods, etc.)?
These factors can be used to expand
your offerings to attract a wider range
of merchants while continuing to
focus on these core factors.
3. Market Segment Analysis
Certain market segments receive more
competitive solicitations than others.
New business start ups, independent
restaurants and bars, and “Main
Street” retailers often don’t go a day
without receiving a payment
processing solicitation. Other types of
merchants, such as manufacturers,
B2B suppliers, government contractors
and other hard to reach businesses
typically do not receive many
competitive offers.
The more competitive solicitations
merchants receive, the more likely
they are to leave. In addition to the
revenue stratification described above,
retention strategies should be focused
around those merchants receiving the
greatest number of competitive
solicitations – whether by phone,
direct mail or in person.
4. Services Provided
It is commonly believed by industry
experts that the more services an ISO
can provide to a merchant, the more
likely the merchant will remain with
that ISO. More services also generate
more margin and revenue.
Are you solely a card processing
provider? Add related and ancillary
merchants. These products and
services can include:
PIN pads for retailers who
do not accept debit today PCI compliance services
and SAQ assistance Electronic gift and loyalty
programs
Online statements and
reporting
Check processing services
including verification
and/or guarantee
Recurring billing and ACH
processing
Insurance verification
services for medical
merchants
Increasing your account services
penetration – or “hooks” into a
merchant – significantly decreases risk
of attrition while increasing margins
and revenue.
Payment processing industry trade
shows, such as the Electronic
Transaction Association’s annual
conference, as well as regional trade
shows, provide a great introduction to
these services and many more.
Internally Focused Strategies
While focusing on merchants is vital in
retaining merchants and preventing
margin compression, reviewing and
focusing on internal factors can also aid in
mitigating declining margins.
Internal factors reviewed should include:
1. Reduce Costs
Since margin is the difference between
fees collected from an ISOs merchants
and the ISOs costs (interchange,
processing fees, third‐party servicing
costs, etc.), an ISO can increase margin
by decreasing costs.
Review existing vendor agreements
such as core processing services
(authorization, settlement, etc.) and
third‐party agreements (gateways,
ancillary services, etc.). Is there an
opportunity to obtain a reduction of
fees due to the changes in market
conditions? Are you nearing the
expiration of the agreement, opening
the door for renegotiation? Are there
less costly alternative options? Have
there been increases in your volume or
transaction count?
ISOs should “shop” on a regular basis,
just as merchants do, to be certain they
are receiving the best combination of
services and low costs. ISOs of
significant scale can often leverage a
conversion of their portfolio to another
provider (if the agreement allows for
this) in order to receive competitive
bids and often garner a fee decrease
from the current provider. 2. Identify Core Strengths
Determine the core strengths that you
utilize to bring value to your
merchants at either the point that they
purchase your solutions or those they
enjoy through the on going delivery of
value of services. What are your
strengths: technical creativity and
merchants? Is it after‐sales support
through incredibly trained support
staff? Is it providing your merchants
superior analytics on their cost of
acceptance such they can reduce
overall acceptance costs? Regardless of
what the strengths are, they should be
used to further differentiate your
offerings from your competitors, while
adding value to your clients. By
distancing yourself from competition
it will put less pressure on price and
therefore less pressure on margins. 3. Evolve Your Offerings
ISOs should conduct regular analysis
and audits of their product and service
offerings. Is your offering stagnant?
When was the last time you
introduced a new product or service to
your existing merchant base or your
sales staff? Has your products and
service offering to merchants kept
pace with their evolving product and
service needs? For example, ten years
ago, data security compliance was not
a key topic for large merchants,
however, over the past decade it not
only is key for large merchants, but
has now gone down market to small
markets. Has your offer kept pace
with your competition? Your
competition is certainly looking to
outpace you. As evidence, a brief
review of the many industry
periodicals highlight new innovation
that your competition is bringing to
the marketplace.
4. Enhance Sales Force Training
Proper sales training sometimes takes
a back seat during periods of rapid
and aggressive sales force expansion,
primarily due to limited financial and
time resources. However, despite the
payment processing industry’s
complexity, proper sales
representative training is vital to both
efficient merchant acquisition and
maintaining sufficient processing
margins.
Historically, the use of contract (1099)
sales representation has been popular
among ISOs as a lower cost vehicle to
grow its sales force. Too often, ISOs
have minimal oversight to the sales
training, selling tactics and pricing
models utilized by these contractors as
they are not employees. However,
ISOs should review their training
programs, test competencies and
ensure consistent delivery of the ISO’s
selling proposition. For example, if
the ISO’s products and service
offering is based upon a very
consultative sales approach through a
clear understanding the merchant’s
payment processing needs and goals,
but its sales distribution channel has
not been effectively trained to carry its
message or desired approach to the
market, it will not likely meet its
objectives as intended. Instead it
might result in a vastly different
approach of selling by its sales
distribution channel barking, “low
prices, low prices, low prices!”
Several suggestions of enhanced sales
training are product and services,
sales and selling proposition. More
specifically, products and services
and services work and the benefits
that are provided to the customer.
Sales training can entail how to
prospect, engage and close an
opportunity. The sales proposition
training educates sales representatives
on the ISO’s marketing message to its
prospects and customers. The selling
proposition is the market based
positioning that enables the ISO to be
uniquely different from that of
competitors in the payment processing
space. It is imperative that the sales
channel, whether it is contractors or
employees, understand the selling
proposition so it can effectively
communicate it to prospects and
clients.
Today, through technology, a number
of lower costs sales training programs
can be developed. Several technology
examples include long distance
“classroom” learning over the internet,
“push based” tutorials delivered to
sales professional’s desktops or mobile
phones. These training tools can be
used to train, certify and periodically
recertify a sales representative’s
knowledge on existing products and
services, new products and services or
the sales process and selling
proposition.
Summary / Conclusion
Although many ISOs report a recent
increase in margin compression, there
are many strategies that may prevent it.
By changing market focus, ISOs have the
potential to tap into newly established
and rarely sought after merchants. In
addition to less competition in selling
to these individual merchants, there is
also a great opportunity to build
profitable referral relationships and grow
the overall portfolio. With existing
economic conditions, there are many
startup businesses to solicit.
ISO sales reps can demonstrate their
value to both potential merchants as well
as their employer by abandoning the ʺlowest priceʺ selling proposition and
developing a strategic partnership with
potential merchants. This not only
drives the merchant to sign and retain
the relationship, but generally leads to
higher margin earnings. After the
relationship is established, there are a
number of strategies that can be used to
prevent margin compression. Those
strategies can be developed by routinely
analyzing merchant profitability,
merchant retention and the need for
more updated services and offerings. Internal practices factor into controlling
margin compression as well. It is
important to routinely examine costs,
identify and build upon the strengths of
your company, analyze and update
offerings and continually improve sales
training.
Taking into consideration both internal
and external factors, ISOs undoubtedly
have the ability to influence margin