Datastream is a marketing data company that has been providing permission-based audience records for over 15 years. It offers a variety of data products including opt-in email lists, telemarketing lists, internet advertising data, and direct mail lists. Datastream's database contains over 1 billion records and offers up to 400 selectable demographic, geographic, and other variables. It also provides services like targeted email campaigns, sales lead generation, and data analytics to help clients execute effective marketing strategies.