As mentioned above, advertising is an excellent way to create revenue, and sites like myspace and Facebook have made great use of this revenue source. Many of the sites on the Internet, in fact -- perhaps even the majority, though this claim cannot be made with any certainty here -- rely solely on advertising revenue for their operation. Many sites and Internet services that have a tiered membership system like those mentioned in the article, with basic membership or services offered for free and more complete and/or extensive benefits offered for a fee, are often supplemented by advertising as well (with the lack of advertising offered as one of the perks for paying for membership). The email/search engine site Yahoo! Is a non-social networking site example of this type of tiered-membership/advertising supplemented...

The authors also contend that these sites must become ever more effective at connecting people with interests, groups, and other individuals that share interests, pursuits, or other common factors, becoming better at connecting "supply to demand," as the authors themselves put it. This requires having an extensive enough network with enough complexity (i.e. interconnections) to make analysis worthwhile.