customers use Bitcoins because they can figure out that this things might be their answer to their savings and other
benifits of it.
I do not see a retailer charge less for using the bitcoin even though they pay less transaction fees. but I do not mind.
I mostly only use retailers who offer a discount for bitcoin. Sometimes it is a little hidden until checkout, but look closely, many places do this and I have saved hunfreds of dollars this way.