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.
Still others rely solely on paid membership subscriptions.
Opinions and usage of online dating services also differ widely.
In Eastern Europe, popular sites offer full access to messaging and profiles, but provide additional services for pay, such as prioritizing profile position, removing advertisements, and giving paying users access to a more advanced search engine.
However, Sam Yagan describes dating sites as ideal advertising platforms because of the wealth of demographic data made available by users.
There are mixed opinions regarding the safety of online dating.
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.