and why do you want to see those statistics? You can really make your own research by your own on their sites,
if they allow the users to take an eye over those.
An increasing number of retailers (mainly online) are starting to accept bitcoins. But is there any actual research to show accepting bitcoins increases sale of goods.
I dont think that there is something "special" about seeing this kind of information, well, maybe they wont expose this because their competitors could take advangate of that.
But bitcoin can not increase the sales actually, only because of the fees, nothing more.