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.
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.
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.
The 2016 Pew Research Center's survey reveals that the usage of online dating sites by American adults increased from 9% in 2013, to 12% in 2015.
Further, during this period, the usage among 18- to 24-year-olds tripled, while that among 55- to 65-year-olds doubled.
Introduction sites differ from the traditional online dating model, and attracted a large number of users and significant investor interest.
In Eastern Europe, popular sites offer full access to messaging and profiles, but provide additional services for pay, such as prioritizing profile position, removing advertisements, and giving paying users access to a more advanced search engine.