I'm considering putting together a nicely-designed directory that is geared towards a single type of merchandise. (I won't be specific as I'm trying not to let the word get out - it is not a questionable line of business)

My goal would be to get merchants with product websites to bid for listings on my directory so that they can get people to click through to their site. I know that I can get some decent traffic to the directory.

Does anyone know of a directory that uses the bidding model and targets product vendors, rather than webmasters looking for SEO? I'm looking to see if anyone else has had success doing this.

Any thoughts on my business model in general?

Sorry for such a long first post - just trying to be clear. I couldn't seem to find anything on this topic in my searches. I'll certainly try to contribute to the forum if I can be of service.

Thanks!