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.
Most services offer digital messaging, while others provide additional services such as webcasts, online chat, telephone chat (VOIP), and message boards.
Members can constrain their interactions to the online space, or they can arrange a date to meet in person.
Some have a broad membership base of diverse users looking for many different types of relationships.
Most free dating websites depend on advertising revenue, using tools such as Google Ad Sense and affiliate marketing.
Since advertising revenues are modest compared to membership fees, this model requires a large number of page views to achieve profitability.
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.