[sgornick]

Merchants incur expenses dealing with cash as well, so accepting $0.98 worth of bitcoin might be equivalent to accepting $1.00 in cash and coin after the hassle of dealing with cash in factored in.

It will be some time before we see bitcoin used at retail, point of sale. But it really solves problems for online purchases -- for the merchant. And maybe that's where the the sweet spot is. If you want what the merchant sells and the merchant wants bitcoin (for the reasons you state -- protection from fraudulent customer chargebacks), you won't be given the opportunity to use your credit card.