Content in digital form like pictures, music files, videos, software etc. from a plurality of content providers (110) is sold to a plurality of users (130) over a communication network like the internet. The content provider submits to a service provider (100) information about the content to be sold and the service provider provides controlled user access to the content for sale under the conditions defined by the information submitted by the content provider. Purchase data about sold items are stored and the user authentification and payment process for all content providers is carried out centrally through a payment system (120) thus offering low transaction costs.