Topsites often list a top 50 or top 100 most popular sites with a similar topic. They can be a significant source of free targeted traffic for member sites if that topsite becomes popular. After several early search engines failed, some people thought topsites might replace them.
Site ranking method is decided by the topsite owner, with votes compiled in a variety of ways. Many topsites have a limit of 1 vote per person within 24 hours. A vote is usually cast by a click of a button graphic or logo. Rankings can be determined by several methods, including:
Besides free incoming traffic, approved members of a topsite can usually display a web banner ad and site description. Many topsites allow a random choice of participating sites to be featured at the top of each page with a description and banner ad. The 88x31 button has become the standard vote button size in topsite culture. The advantage here is the topsite will show the member's larger standard-size banner (468x60) in return for the member displaying their smaller vote button. This allows members to join several topsites without cluttering their page with large banner ads, while maximizing their exposure on each topsite.
Topsites vary widely in both subject matter and quality. Some topsites are run on auto-pilot, with any site allowed to join automatically (which will lead to spam problems). Others have a strict requirement as to which websites are allowed to join. Often, only websites sharing the same topical theme or geographical area of the topsite itself are invited to join. Unless well maintained by the list owner, topsites quickly suffer from link rot and, as a result, become unreliable for typical visitors. Seeing many broken images can be an indicator of low quality.
Recently, numerous chat websites in Europe have been trying to join multiple topsites as a way to quickly get more incoming links and boost their site popularity for search engine rankings. Ignoring a topsite's theme or requirements to sign up unrelated websites is considered spam.
Topsites should be considered a valuable resource in niche web marketing, typically they have all the benefits of a directory but have the advantage of a dynamic, user powered ranking system which encourages a steady flow of traffic to related sites.