Sitefinity is an ASP.NET based content management system (CMS) developed by Telerik, perhaps the best-known vendor for .NET controls and components. Unlike most CMS, Sitefinity is not free. However it offers support, which the open source projects do not, and that is a big draw for many businesses and organizations.
Other advanced features that are offered by Sitefinity which other systems rely on third parties to facilitate include e-commerce and email campaign management. By creating a one-stop-shop and professional support, Sitefinity is able to entice many companies to forgo their free options and shell out the money for a license. This can often be a wise decision for companies without development or IT professionals easily on hand.
Having installed and customized many content management systems, the development and web team at Planet Telex can attest to the fact the Sitefinity is a top-tier offering and is generally easy to work with and customize. Having a company standing behind and supporting the code they distribute can be refreshing compared to the open-source DIY culture of other CMS. Whether it is worth the cost of a license is a decision that can only be made upon review of your needs and available resources.