Eharmony is one of the most popular dating sites on the web. Founded in 2000 by psychologist Neil Clark Warren, Eharmony provides single people with the opportunity to meet others with whom they are predicted to be compatible. Neil Clark Warren’s theory of compatibility, developed over 35 years of working as a marriage counselor, is the basis for the algorithm on which matches are made.

In order for a user to become part of the Eharmony family and become eligible for meeting compatible suitors, a 258-question profile must be answered. Many people are in fact rejected as completely inappropriate for matching, and until recently, Eharmony did not accept gays or lesbians at all. Many people also claim that those who answer the profile with answers implying they are not religious will be rejected.

Eharmony has a number of dating resources and articles by “experts” in relationships, dating, and marriage. Much of this information is not available unless the profile is completed (and passed) and fees are paid for the service. The site also provides a list of “Success Stories” profiling couples who met on Eharmony and eventually married.

Eharmony’s visitors are mostly female (66%), and 43% are between the ages of 35 and 49. Four out of five visitors are Caucasian, and 78% have no children. Almost half of the 4 million monthly visitors are college graduates.