People aren't necessarily asking for a business. They're asking for a business model: a way, maybe untested, maybe lightly tested, that you might earn more than you spend. Just needs to be semi-plausible, doesn't need to be bulletproof.
If you don't care about whether it's tested this startup had a plausible business model: by coming up with an algorithm to identify fashion taste, fashion e-commerce sites could show more relevant recommendations, which leads to more sales, which leads to more revenue. Then they pay this company some fraction of that additional revenue, and both win.
