Stripe is 2.9%+30¢ right, and that’s the advertised rate. So I assume any business seeing averages higher than that can be avoided by using a platform like Stripe.

The Stripe rate is a careful blend. There are many cards that are cheaper to process and there's probably a few that are more expensive to process at that rate, it works out in the wash in favor of Stripe. Also, that 30 cents is a large percentage if you're looking at a $5 transaction, for example (6%!)

See the "raw" rates here: https://www.mastercard.com/content/dam/mccom/us/business/doc...

Small merchants are people, and people vary in their intelligence/savvyness and may have other issues like poor credit or high chargebacks that they usually forget to mention. Some people roll the cost of the terminal into a higher fee as well.

I helped out a friend who owns a deli when he took over from his parents. His dad saw cash as a way to avoid taxation and had some awful payment processor where they paid a high fee and was renting a POTS based terminal - $60/mo to Verizon and $30/mo for the terminal.

Now he keeps one set of books, and raised his average sale by about 10%. Their catering business, which drives profits, are up significantly with online ordering through the POS.

Ditto with a non-profit I was on the board of. Pushing Venmo and Square for donations increased donations by like 30% and reduced shrink at fundraisers. Anyone who claims they can’t afford a 3% fee is going out of business anyway.