Ha, eBay has it's own local product search now. Google does too.
Amazon doesn't, Facebook doesn't, Yahoo and Microsoft? Nope.
I smell more acquisitions.
Wow. How are you getting the inventory data from the stores? Especially small ones? I can understand how big guys are submitting the data but mom'n'pops?
And are you sure you really have 15,000 stores? Number seems too big to me for just one US region, even that NYC is quite large. Milo and others are claiming around 50,000 locations in the whole US.
Why just not parse/index all the products from stores websites and verify in-stock real-time when making a search via script or something (given that in-stock availability is indicated). Using this approach you can collect product/location data from more than a million stores I would guess. No?
Hm. Seems like these Russkies are using some kind of "secret sauce" crawler/parser? And it does check "in stock" info on-the-fly? Plus stores are not even involved in the process of aggregating the inventory?