2% fee's will solve all the BTC problems: slow-confirmation-risk, seller-risk, etc. Mom&Pop will use it. *Not* because BTC is so great but because there is no reason not to use it (a bit like PayPal).
With a 2% fee there is absolutely no reason to use it. Merchants gain nothing but added complexity and expense. They can simply keep using PayPal. The largest advantage for merchants is a significant boost to their net margins by the removal of the 2% overhead by bypassing the credit card network. It makes no sense to bypass the credit card network to pay the same amount in fees to a different third party. Merchant adoption would be essentially zero.
Not entirely. Merchants may adopt it at 2% for the same reason they adopt AMEX at 3%.
But even if we agree that 2% *is* the limit and that merchants have no reason to adopt..... that doesn't mean we are back to 0%.
we have a zone of possible agreement between 0-2% of most consumer transactions. All that value is created by BTC. We'll see how much gets claimed by the consumer, by the seller, and how much by the middle men. It will (i.e. should) depend on who has a better alternative to adoption.