Profiles created by real humans also have the potential to be problematic.
For example, online dating sites may expose more female members in particular to stalking, fraud, and sexual violence by online predators.
Still others rely solely on paid membership subscriptions.
Opinions and usage of online dating services also differ widely.
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.