Hello
I own a web hosting directory. It is not very popular but receives 40-50 unique visitors every day. Alexa's raking is around 370.000. Visit duration is (majority) 5-15mn. I am wondering if the site could get possible advertisers from hosting firms.
Thanks

A URL would be most helpful......

Very hard to bring in some results for the Advertiser at this minimal stage. Unless you are a pay-per-click engine and companies pay you per click. For instance, I usually wait till I get to a 500 uniques daily level (on any project i work on) before even thinking about money. But hey, most directories do what you plan to do - they charge from the beginning and try to spend those money on advertising themselves.

Good luck!