[zanny]

Lower prices (but that requires complete adoption or significant enough adoption vendors want to stop supporting credit card companies and thus increasing their prices) and the ability to transact with anyone, anywhere, anytime.

[sanswork]

One of the problems with the price angle here is thinking that credit card companies can't compete on price or are at the minimum amount they can charge profitably. Visa has a net profit margin of like 50%. They could even restructure to require banks pay them a chunk of interest payments and offer merchants 0% fees if they wanted.