Profiles created by real humans also have the potential to be problematic.
For example, online dating sites may expose more female members in particular to stalking, fraud, and sexual violence by online predators.
Over 50% of research participants in a 2011 study did not view online dating as a dangerous activity, whereas 43% thought that online dating involved risk.
Because online dating takes place in virtual space, it is possible for profile information to be misrepresented or falsified.
Most free dating websites depend on advertising revenue, using tools such as Google Ad Sense and affiliate marketing.
Under this metaphor, members of a given service can both "shop" for potential relationship partners and "sell" themselves in hopes of finding a successful match.
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.
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.