I was thinking of creating a database of beauty bloggers. It would contain info such as the pricing for advertising and user statistics for each blog. There would also be a functionality for the companies to rate bloggers on the effectiveness of the campaign. Would companies be willing to pay for such a platform?
Beauty isn't my field -- not the cosmetic / fashion variety, anyway.
But I see companies from other industries eager to pay bloggers for advertorials. So I assume that the same demand exists in the industry you're examining. I'd also imagine that such a database would make the process of connecting advertisers and bloggers much more efficient. If I'm right, then you have a promising idea.
But you ought to be asking (1) the bloggers and (2) the companies who'd be paying to advertise. If they think it's a good idea, then you're off to a good start.
Then you'll want to research existing platforms (if there are any) and assess your own readiness to build and market the service you have in mind.
P.S. If you get to the stage where you're thinking of a brand name for your project, talk to me. That is my actual field. So the beauty that primarily catches my eye is VERBAL beauty.
There already are some platforms that do this - not specifically for beauty, but in general. Companies pay Triberr for the ability to recruit bloggers who use the platform to write sponsored posts.
Blogdash serves as a platform for bloggers and for companies/brands to connect, so companies can find bloggers to review products (transparently, of course).
So the short answer is, most likely yes. However, you'll want to do more research to see what other platforms there are out there (these are just two that came to mind off the top of my head; I'd imagine there are some others). There's plenty f due diligence to be done yet.
That said, beauty seems to be one of those industries that truly appreciates targeted services - those that are meant specifically for the industry. So I'd encourage you to do more investigating and, as Joseph mentioned in his response, speaking to the potential bloggers and companies you'd be connecting on the platform.