With no money paper trail leading to a dating site for their partner to find, it is easier for them to hide their infidelity.
Scammers and fraudsters also love the free dating sites due to the zero cost of entry.
No dating site wants them but the free sites usually do not have the resources to detect them and deal with the problem.
Plus, if the site finds a scammer and then bars the member, the scammers have lost nothing as they will just log in the next day and just create another account.
Since these dating sites make their money off of the advertising on the site, this leaves little resources for important things like customer service and improving how the site functions for its members.
This means the only thing preventing someone to join is the time spent to fill out a page to register.
With the sites and apps listed below, they range from having tens of thousands to millions of members.