Still others rely solely on paid membership subscriptions.

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.

Such companies offer a wide variety of unmoderated matchmaking services, most of which are profile-based.

Online dating services allow users to become "members" by creating a profile and uploading personal information including (but not limited to) age, gender, sexual orientation, location, and appearance.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.Niche sites cater to people with special interests, such as sports fans, racing and automotive fans, medical or other professionals, people with political or religious preferences (e.g., Hindu, Jewish, Christian, Muslim, etc.), people with medical conditions (e.g., HIV , obese), or those living in rural farm communities.In 2008, a variation of the online dating model emerged in the form of introduction sites, where members have to search and contact other members, who introduce them to other members whom they deem compatible.Some sites are completely free and depend on advertising for revenue.