Yeah, and even for non-clothing things, you might be able to make a really cool system that retailers can sign up for to list their inventory with you, so that people have an awesome online way to find things they'd otherwise just buy on Amazon in a brick and mortar store, they can get to today.
We use image recognition and scrape items from social media, partner databases and crowdsourcing.
Also testing with Beta users to snap what they're wearing and let them tag semantically ("night out","office","summer wear", "goth").