Last time I checked, there was no discount for using bitcoin.  For me personally, there was no incentive to use bitcoin.  As a bitcoin enthusiast, however, I always check Overstock and Newegg first when making a purchase...and I use $US.  Why should I spend BTC which I value when I have USD to dump on them?  Why should I spend the exchange fees to purchase BTC and send it to them?

So the 1% direct sales is just another small part of a bigger picture that can only be estimated, much like all things decentralized, open source, and bitcoin.