Other sites target highly specific demographics based on features like shared interests, location, religion, or relationship type.
Online dating services also differ widely in their revenue streams.
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.
That is, online dating sites use the conceptual framework of a "marketplace metaphor" to help people find potential matches, with layouts and functionalities that make it easy to quickly browse and select profiles in a manner similar to how one might browse an online store.
Under this metaphor, members of a given service can both "shop" for potential relationship partners and "sell" themselves in hopes of finding a successful match.
Most free dating websites depend on advertising revenue, using tools such as Google Ad Sense and affiliate marketing.
Since advertising revenues are modest compared to membership fees, this model requires a large number of page views to achieve profitability.
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 number of tasks, and less likely to use such a service if they are trusting of others.
It is possible that the mode of online dating resonates with some participants' conceptual orientation towards the process of finding a romantic partner.
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.
A great diversity of online dating services currently exists.