Method and apparatus are disclosed for contacting users based on the completion of an online session, such as an Internet session. A user begins an online session by logging into an access provider, such as an Internet Service Provider. Upon completion of the online session, the access provider can store online session data that describes the online session. The online session data may include such information as the identity of the user (e.g., a phone number, an address, and so forth) and the time the online session ended. This online session data can be processed by a caller in order to identify users to call. The caller may be the access provider or a third party, such as a telemarketer. The online session data may be processed in various manners. The online session data may be compared to data of failed calls to identify users who could not be contacted before, but that may now available based on the completion of their online sessions. The online session data may be processed to identify users having online sessions that were completed within some time interval. The online session data can be processed in other ways.