Most sites allow members to upload photos or videos of themselves and browse the photos and videos of others.
Sites may offer additional services, such as webcasts, online chat, telephone chat (VOIP), and message boards.
The highest scoring dating service was Facebook, which uses the personal homepage genre, the message board genre, the weblog and directory genre, as well as utilizing the Circle of Friends.
The second highest scoring, Second Life utilizes virtual worlds, message boards, chat groups and profile pages to allow people to contact in a three-dimensional environment.
Some sites such as Ok Cupid.com, and are free and offer additional paid services in a freemium revenue model.
Some sites are broad-based, with members coming from a variety of backgrounds looking for different types of relationships.
Other sites are more specific, based on the type of members, interests, location, or relationship desired.
A 2005 study of data collected by the Pew Internet & American Life Project found that individuals are more likely to use an online dating service if they use the internet for a greater amount of tasks and less likely to use such a service if they are trusting of others.
Since 2003, several free dating sites, operating on ad based-revenue rather than monthly subscriptions, have appeared and become increasingly popular.
Several newer sites such as Ok are beginning to offer more full featured dating services for free, and are starting to compete with staples in the free dating site world such as
A German documentary analyzed the market and uncovered multiple problems of online dating sites.