Systems and methods are provided for distributing content such as audio, video, and text files to users over a communications network such as the Internet. Content owners may store content items at content provider computers. A catalog provider computer may be used to host a catalog that lists the various content items available from the content owners. Vendors having vendor websites operating on vendor computers may view the content information in the catalog to determine which content items to offer on the websites. Users may select a desired content item to purchase at a vendor's website. When a user clicks on an appropriate purchase option, a micropayment service provider computer handles the purchase transaction. The purchased content item may then be delivered to the user from an appropriate one of the content provider computers.