eHarmony was founded in 2000 and is a pioneer in using relationship science to match singles seeking long-term relationships. Arguably one of the first Web 2.0 sites because of its focus on connecting its users, eHarmony matches users together using a rigorous 250+ item questionnaire. It is popular and successful with well over 20 million registered users. eHarmony’s matching system determines members’ compatibility with others based on their values, character, intellect, humor, religious/spiritual beliefs and many other dimensions. In all, it analyzes 29 dimensions of compatibility and synthesizes matches using an algorithm built on 35 years of clinical research.