ONLINE PERSONALS WATCH -- Aug 22 -- Nielsen Netratings is now providing monthly rankings to Online Personals Watch (see column on left). Each month you can expect to see the top 15 online personals site rankings from Hitwise, Alexa and Nielsen Netratings. In addition Hitwise provides enough numbers for us to pull the rankings for some additional categories (defined by Online Personals Watch). These categories are; personality profiling, religious focused, black, asian, gay. We use the Alexa rankings for the social networking rankings and adult dating sites. The methodologies used by Hitwise, Alexa and Nielsen, (and also Comscore) are very different. Hitwise pulls their numbers from ISP's and only ranks by market share. Alexa uses data from it's toolbar userbase and also only gives a ranking score for websites. Nielsen pulls from a panel and extrapolates numbers such as uniques from it's representative panel of tens of thousands. Also note, Hitwise and Nielsen categorise online personals slightly differently so, for example, you'll see TheFaceBook in the Nielsen rankings but Hitwise chooses not to categorise this as an online dating site.