Still others rely solely on paid membership subscriptions.
Opinions and usage of online dating services also differ widely.
Most services offer digital messaging, while others provide additional services such as webcasts, online chat, telephone chat (VOIP), and message boards.
Most services also encourage members to add photos or videos to their profile.
Once a profile has been created, members can view the profiles of other members of the service, using the visible profile information to decide whether or not to initiate contact.
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.
Further, during this period, the usage among 18- to 24-year-olds tripled, while that among 55- to 65-year-olds doubled.
Profiles created by real humans also have the potential to be problematic.