Still others rely solely on paid membership subscriptions.
Opinions and usage of online dating services also differ widely.
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.
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.
However, Sam Yagan describes dating sites as ideal advertising platforms because of the wealth of demographic data made available by users.
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.
While some sites conduct background checks on members, many do not, resulting in some uncertainty around members' identities.
For instance, some profiles may not represent real humans but rather "bait profiles" placed online by site owners to attract new paying members, or "spam profiles" created by advertisers to market services and products.
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.