Other sites target highly specific demographics based on features like shared interests, location, religion, sexual orientation or relationship type.
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 they may be fake "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.
At the end of November 2004, there were 844 lifestyle and dating sites, a 38% increase since the start of the year, according to Hitwise Inc.