I found for you a 10 minute video that explains for merchants how the process of accepting credit cards actually works.
The video presents a lot of information about what happens from the moment a customer presents his credit card, through to the purchase being authorized and you, the merchant, being paid.
It then goes on to discuss in pretty detailed manner the various fees that are charged, how they are determined and how you can better understand the monthly statement that you receive from your merchant account provider.
For most merchants, the information here is probably new to them.
Many merchants view the merchant account application process as something to get done as quickly as they can, and without bothering to really understand the fees they are agreeing to pay.
Hopefully, this video will help educate them. Enjoy!