There are hundreds if not thousands of contextual programs out there. These programs pay you for putting their ads or links on your site. One common one is Google AdSense and another one is Yahoo! Publishers network. There are also hundreds of others one. Using good seo tools, and website design experts can really help you with your sites. You can sell more ad space and get into many contextual programs along with attracting traffic and members. Contextual programs are a great thing to start with if you are a blogger and would like to get some money. The pay can be great as well. Try to seek out some search engine marketing around the website. This basically means that they will try to get you more visitors from search engines and you can end up monetizing the sites with the contextual programs.
Good luck to those new to contextual programs, look for more posts here where i explain more into the programs and give a list of some as well.