People normally do this on facebook using the photos feature It would be a website that is basically for doing that and learning about what your friends just bought and been able to know cool new products or clothing. The ladies always want to know what their friends think of their dresses or makeup while the men love to know what other think of his new perfume, suit or car.

What's the current competition? In other words, is there another site doing something similar?

Presently i can't find anyone doing with the same idea..

I couldn't either. I'd be interested in helping you develop this idea further if you're interested in a technical co-founder.

You can find my contact info on my site ryanleland.com