Business Insider had published "The 2012 Digital 100: The Complete List"
#37 Zoosk, is a deflating bubble, a HOAX. Zoosk is not a Scientific Matchmaking Service/System. Zoosk will be a "stupid investors case of study" for several venture funds.
#63 eHarmony is a 12+ years old obsolete site, and a HOAX. Recently they made a mistake and revealed eHarmony's secret sauce. (the effectiveness/efficiency of the matching algorithm.)
"99.7% of eHarmony’s members will not be introduced to you (translated from the failed Japanese site)", i.e. only 0.3% of members will be shown as a compatible partner for you; that is the power of eHarmony's matching algorithm (the effectiveness/efficiency of the matching algorithm.)
0.3% means: 3 persons per 1,000 persons screened in the same range as searching by your own! eHarmony’s matching algorithm performs really as placebo.
#97 As for PlentyOfFish, its compatibility matching predictor is a HOAX and the entire site is a MESS, the owners are conducting a big human experiment with unprecedented consequences and should be denounced in several Consumers' Associations Worldwide.