Online forums around brands (aka fan sites) - everything from Tyra Banks to Bratz are big business. Anyone that has searched for information on google or yahoo will realize that forums represents a disproportionate portion of the search results due to the large amount of dynamic & fresh content generated. All if not most are moneitzed through YPN or Adsense - Google ’s Adsense is generating around $4B a year for Google and probably $8-$12B in total for millions of webmasters. To realize how big this “digital underground” is all we need to do is to take a stroll on sitepoint or webmasterworld. (Monetizing the longtail of websites if you well!)

Foremanski has some good comments from the business perspective.

There is, however, something more going on here from search marketing perspective. . .

1. Yahoo can give preferential treatment to these sites over independent fan sites and forums. Try a Maria Carey search on Yahoo and you will notice the Yahoo Artist page as the top result. This will happen to a lot of top search terms going forward.

2. Even Google will give these sites higher rank compared to independent sites because they are hosted on a yahoo domain which has high PageRank (wii.yahoo.com for example)

3. Having the search term in the subdomain (wii.yahoo.com) could potentially increase search ranking as well (somewhat debatable)

4. Conversely, this could be considered a form of cyber squatting (a subset of the copyright issue widely mentioned) given the brand name in the subdomain

5. Yahoo will for sure expand this down its list of search terms and eventually extract more and more value and advertising dollars from webmasters who runs these fan sites and forums.

Time will tell but this could be a turning point for the large community of niche sites having their way until recently on drawing internet traffic away from larger commercial website. . . Yahoo is fighting back and so are other media companies (note the recent spat of “social networking” initiatives from media companies)