It’s not a good idea!
We tell clients constantly that they should develop a website that will attract users for the content and that they should focus on finding ways to keep that user coming back. Like many clients, we have tried a number of different techniques to generate revenue using the internet. I created a number of directory based websites whereby the users would use the directory to locate a business that they wanted to work with. For the a low investment, the business could establish an online profile and thus obtain traffic to their site. The business could also raise their profile by raising their investment. This has worked for only a few sites on the internet and it’s rather difficult to pull it off.
At least once per month we receive an inquiry here to create such a site and we always dig deep into the concept, the projected user base, the projected client base, and the business plan. The sole reason for digging deep is to clearly identify to our client the reasonable expectation of performance for the website.
Below is an excerpt from useit.com and how they perceive the advertising website and whether it will be successful.

“The number of companies that chase the same advertising dollars as their only business model is a sure sign that we’re at the peak of Bubble 2.0. It would be much more sustainable if companies aimed to create services that users valued enough to pay for.
Right now, considerable advertising money is sloshing through the Web because most marketing managers remain clueless about how it works. They think that because search advertisements generate lots of business, other Web ads must work just as well. What a fallacy — brought on by ignorance of the basic Web user experience. People go to search engines when they’re explicitly looking for a place to do business. This is why search engines profit from sucking up the work of content sites (where users exhibit strong banner blindness).
Marketing managers won’t remain clueless forever. Sooner or later they’ll discover that Web advertising offers almost no ROI. Only two forms of Web ads actually work: search ads and classified ads (such as eBay and real estate listings). A third type of Internet advertising that might work are video ads, because video is a linear media form (in contrast to nonlinear website navigation). At this point, we don’t have enough user research about Internet video to say for sure.”