I don't see that as adding anything useful to the Internet. These days, site after site is one huge advertisement for an endless stream of products and services. Often we have no idea whether we can trust the opinions given. That's the bad side. The good side is that programs do exist for high quality services and products.
Webmasters can make their sites more useful by offering such programs.
The webmaster could try these services and offer testimonials. An excellent example is Lynch Consulting , which was the top money-earning associate recently for the Internet News Bureau. Here's another example. When I looked into ways companies can set up their own associate programs I contacted a number of companies and asked for testimonials. I received very strong recommendations for Craig Belcher's Affiliate Link, Paul Galloway's software and Be Free.