Some sites are completely free and depend on advertising for revenue.Others utilize the freemium revenue model, offering free registration and use, with optional, paid, premium services.

While some sites conduct background checks on members, many do not, resulting in some uncertainty around members' identities.

For instance, some profiles may not represent real humans but rather "bait profiles" placed online by site owners to attract new paying members, or "spam profiles" created by advertisers to market services and products.

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.

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.

Other sites target highly specific demographics based on features like shared interests, location, religion, or relationship type.

Online dating services also differ widely in their revenue streams.

Still others rely solely on paid membership subscriptions.