These are free websites that post links to commercial sites, providing a sampling of the commercial site in the form of thumbnail images, or in the form of Free Hosted Galleries—samplings of full-sized content provided and hosted by the commercial sites to promote their site. Some free websites primarily serve as portals by keeping up-to-date indexes of these smaller sampler sites. These intents to create directories about adult content and websites were followed by the creation of adult wikis where the user can contribute their knowledge and recommend quality resources and links.