Gert-Jan Munneke is the brother of Michiel Munneke. He started Traffic4U while he was studying Business Administration at the University of Groningen. His company started as an e-travelling agent, and later transformed into a search engine marketing company.

At the moment Gert-Jan is the owner and CEO of Traffic4U, the market leader in search engine marketing in the Netherlands. Traffic4U was ranked 6th in the Deloitte technology fast 50 of 2006. Currently there are 70 people working at Traffic4U, and the company keeps growing at a quick pace.