Freeserve has parted company with advertising network operator DoubleClick. It will continue to use DoubleClick’s DART ad serving software, but the UK’s biggest Internet service provider (ISP) is to bring sales operation in-house from June 1. The ad sales team is being increased from nine people to 40. Freeserve claims it generates more than 50 per cent of its revenue from ads. Revenue also comes from taking a cut from the dial-up fee. The ISP, which has 1.9 million “active members”, will soon need to generate even more of its revenue from ads when unmetered access takes hold in the UK.