Opinions and usage of online dating services also differ widely.
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.
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.
Introduction sites differ from the traditional online dating model, and attracted a large number of users and significant investor interest.
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.
Most free dating websites depend on advertising revenue, using tools such as Google Ad Sense and affiliate marketing.
Members can constrain their interactions to the online space, or they can arrange a date to meet in person.
A great diversity of online dating services currently exists.
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.
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.
Most services offer digital messaging, while others provide additional services such as webcasts, online chat, telephone chat (VOIP), and message boards.
Some have a broad membership base of diverse users looking for many different types of relationships.
Other sites target highly specific demographics based on features like shared interests, location, religion, or relationship type.