Its incredibly hard to convince anyone to use bitcoin, especially businesses. Fact is...they want reliability. Just discussing the fact the the market fluctuates daily is enough to make them ignore me. Ive tried talking many sites into doing it 
Perhaps we could start an organization established by donations that will back/insure BTC, I guess it is a little like the FDIC, however all funds are private and since we all have a vested interest in the currency I dont see a problem with trying to increase its value.
say the group could only afford to insure 3 online stores at first(it will depend on the products offered), that will still be a huge positive for BTC, the movement would grow which in turn would bring more retailers and raise the value of the currency.