Set up a web directory.
A web directory is not a search engine and does not display lists of web pages based on keywords; instead, it lists web sites by category and subcategory. (Source: wikipedia.org)
After setting up the web directory, promote it so that it’s getting a decent number of regular visitors, and then charge a fee for advertisers to list their websites in your directory. The directory can be general, like botw.org or subject specific like a web hosting directory.