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.

There are mixed opinions regarding the safety of online dating.

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.

A great diversity of online dating services currently exists.

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.

Further, 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.