I created a wikipost after a more in depth review of the actual settlement text (which I linked in said Wikipost). It seems even weaker than I thought in my last post, because it's not four basis points reduction per year for three years, it's four basis points on the posted interchange rates for that entire period. The seven basis points is an average of all Visa/MC credit acceptance including fixed fees (10 cents per transaction in addition to a percent, for example), unavoidable network fees, etc... so this is really quite small. Essentially the 4 basis points in the three years (4bp total) is a subset of the reduction of 7bp average effective including fees (7bp total) for five years.

I would note that the settlement text allows merchants to enter a pilot to not accept Visa/MC debit/other non-credit Visa/MC products at all of their locations, initially starting as a pilot limited to 20% of outlets under a single banner/brand, but the surcharging term changes in this settlement apply exclusively to credit. So if a merchant is accepting Visa/MC debit, it won't change that these products are still not allowed to be surcharged (which many merchants do anyways, violating Visa/MC network rules).

Again, in practice, for any merchant that accepts Visa/MC/both in addition to Amex - surcharging is de facto not allowed. If they follow Visa/MC network rules and don't surcharge debit, they're breaking Amex network rules that all cards must be surcharged. If they surcharge all debit including Visa/MC, then even after this settlement, they would be violating Visa/MC network rules.

I guess that the possibility for merchants to decline to accept Visa/MC debit would allow a theoretical situation where a merchant declined to accept Visa/MC debit but accepted Visa/MC credit, surcharge Visa Credit/Mastercard Credit/all Amex, and that would be kosher with both networks (MC/Visa you don't accept debit so you can't surcharge it, Amex you're surcharging all other accepted cards equally). The difficulty with this option is that banks with >$10B assets are required to provide secondary networks for debit routing, but issuers with less are not under Durbin Swipe fee reform. Start trying to explain to consumers that your credit union or local/regional bank debit card isn't accepted because it's not from Citi/Chase/BofA/Wells Fargo...

So again, I don't really see this settlement practically changing much in the pervasiveness of surcharging. Most merchants that are violating network rules on surcharging now (most of them due to the Visa/MC and Amex catch-22 on their rules) will still be violating them if they accept Amex in addition to Visa/MC after this settlement.