We tried to do exactly that a couple of years ago. I've no doubt lots of others have tried, it's not an original idea. The problems associated with it are legio

We tried to do exactly that a couple of years ago. I've no doubt lots of others have tried, it's not an original idea. The problems associated with it are legion though. The vast majority of small or independent stores have no electronic inventory system. Lots of store owners we spoke to didn't even know what they had in stock, or have a list (electronic or paper) of what they had in stock. And it's these smaller stores which actually make such a service truly valuable. And don't forget - there are thousands, 100s of 1000s of them. getting them all on board is nigh-on impossible. Many the small stores we visited had thousands of items for sale. The job of itemising them is, for a small business, just too expensive and/or time consuming. Additionally most of these owners were absolutely hopeless with technology - they couldn't even upload a csv (what's a csv file?) with a simple web form. Many of them didn't have, nor want a website. It's out of their realm of knowledge or understanding, and they have no desire, in fact often an aggressive rejection of, adopting new technologies. Couple that with the costs involved, they are simply not interested, whatever the business case. This isn't going to happen by virtue of an active sales drive. This is only going to happen passively over the next 10 - 20 years as more stores get unified cash register/inventory systems - and then only if such systems provide a common or standard api for web or mobile platforms to hook into. And this in itself is a huge problem - there is no dominent player in the cash register/inventory business - just hundreds of little guys with no common standards. It's a nice idea and would be wonderful. But it's just too big a project to make a reality.