Unique Features of eHarmony
What makes eHarmony different than most other dating sites is the premise of the site: their matching system. This means there is no search engine, and until recently no way to even see a potential match's photo before making contact.
Many users have complained that eHarmony never has any matches for them initially, which I have personally found to be true as well. There is an easy fix to this problem however: sign up at eHarmony, fill out the questionnaire and demographic information, get your personality profile, and then leave eHarmony alone for a while. By the time you start getting matches (you'll get an email each time the service finds someone compatible with you), you'll also have received several emails offering you a hefty discount to use the service. I wouldn't recommend anyone subscribing to the site without having at least three matches, since oftentimes members don't respond (also in my experience). Then, wait until you receive an offer in your email box, and sign up at that time - and not a moment before.
I highly recommend eHarmony for heterosexuals serious about finding a long term relationship as long as they are aware of the drawbacks listed above. eHarmony's track record is incredible, and their success stories are increasing exponentially, with 90 members getting married every single day because of the site.