Honestly I have no idea what kind of business it would make. It may take off, it may not.<p>IMO though I wouldn't be inclined to use it. First, if I buy something nice, new, or expensive and I want my friends to know about it, I will either put it on Facebook or tell them over the phone or in person. I know everyone I friend on Facebook personally, I have met all of them in person and talk to them at least once a month on average in some setting either via Facebook, email, in person, or on the phone. With that in mind though, of the over 500+ friends I have there, I would only share a purchase with maybe 20-30 of them at most depending on the purchase. I have lists setup on Facebook for all my friends, broken down into groups such as College, Work, Family, etc... From there when I post things to my wall I direct those posts only to those lists, meaning that others can't see the post. So I can control who sees what and knows what about things I do at a very granular level. Even though the average person probably doesn't have this level of granularity setup on Facebook, the thought process behind sharing is probably the same to some extent.<p>As for competition, I think there are several avenues you may not have considered. First, social shopping sites are starting to popup everywhere. Fancy (<a href="http://www.thefancy.com" rel="nofollow">http://www.thefancy.com</a>) is one that I can think of off the top of my head. There is also a site that lets women, and I think men, rate each others clothing choice.<p>Now, I will say that the concept of social shopping is powerful and if you can tap into the market with something unique and powerful you may have your hands on something. I for one know that I usually look to friends when deciding on a major purchase. If you could somehow incorporate a deals functionality, maybe like a Groupon into it, where if you can convince a bunch of friends to buy something you work out a discount with the store, that could potentially take off.