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.Profiles created by real humans also have the potential to be problematic.

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.

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.

Still others rely solely on paid membership subscriptions.

Opinions and usage of online dating services also differ widely.

A 2005 study of data collected by the Pew Internet & American Life Project found that individuals are more likely to use an online dating service if they use the Internet for a greater number of tasks, and less likely to use such a service if they are trusting of others.

It is possible that the mode of online dating resonates with some participants' conceptual orientation towards the process of finding a romantic partner.

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.

That is, online dating sites use the conceptual framework of a "marketplace metaphor" to help people find potential matches, with layouts and functionalities that make it easy to quickly browse and select profiles in a manner similar to how one might browse an online store.