Pizza is one of my favorite foods, my favorite pizza places here in Chicago are Coalfire and Pompei.  Here is my estimate of how much an average pizza shop pays to accept credit cards:

• According to Entrepreneur.com, the average revenue of the 40,164 pizza restauranst in the US was $598K in 2007.
• The 2008 Hitachi Consulting Study of Consumer Payment Preferences (P.6) tells us that the average restaurant collects 58% of it’s payments with credit and debit cards.
• We have several pizza restaurants among our customers.  On average, they are paying 2.33% in interchange.  Unfortunately, as small businesses, most also pay a significant markup to their credit card processors.  For a business of about $500k in annual revenue the markup is on average about 0.90%, although some have a better deal and many have a worse deal.

From this information we can compute that the average pizza restaurant pays around $598K x 58% x (2.33% + 0.90%) = $11,203 each year in credit card processing fees.

Shameless plus – pizza restaurants that used FeeFighters to find their credit card processor pay an average markup above interchange of 0.15% + $0.10 with no-tricks interchange plus pricing.