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. By 2007, many prominent studies show that Baby Boomer interest in online dating have soared.
Other sites are more specific, based on the type of members, interests, location, or relationship desired.
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 amount of tasks and less likely to use such a service if they are trusting of others.
Some sites provide free registration, but may offer services which require a monthly fee.
Other sites depend on advertising for their revenue.
A German documentary analyzed the market and uncovered multiple problems of online dating sites.
Amongst them are "romance-scamming" (persons registering on the sites to get money from people falling in virtual love with them), using controllers or animators registered with multiple fake accounts, using unexpected and sometimes unlawful conditions in the terms and conditions leading to longer contracts a client intended to sign.
Since 2003, several free dating sites, operating on ad based-revenue rather than monthly subscriptions, have appeared and become increasingly popular.
Several newer sites such as Ok are beginning to offer more full featured dating services for free, and are starting to compete with staples in the free dating site world such as
Also, this model generally allows users to switch between free and paying status at will and without having to do anything, simply providing advanced features for a set period of time whenever the according payment is received.