Most services also encourage members to add photos or videos to their profile.
Once a profile has been created, members can view the profiles of other members of the service, using the visible profile information to decide whether or not to initiate contact.
Profiles created by real humans also have the potential to be problematic.
For example, online dating sites may expose more female members in particular to stalking, fraud, and sexual violence by online predators.
Niche sites cater to people with special interests, such as sports fans, racing and automotive fans, medical or other professionals, people with political or religious preferences (e.g., Hindu, Jewish, Christian, Muslim, etc.), people with medical conditions (e.g., HIV , obese), or those living in rural farm communities.
In 2008, a variation of the online dating model emerged in the form of introduction sites, where members have to search and contact other members, who introduce them to other members whom they deem compatible.
Some have a broad membership base of diverse users looking for many different types of relationships.
At the end of November 2004, there were 844 lifestyle and dating sites, a 38% increase since the start of the year, according to Hitwise Inc.
The stigma associated with online dating dropped over the years and people view online dating more positively.
Such sites earn revenue from a mix of advertising and sale of additional options.
This model also allows users to switch between free and paying status at will, with sites accepting a variety of online currencies and payment options.
However, Sam Yagan describes dating sites as ideal advertising platforms because of the wealth of demographic data made available by users.