The agency won in a pitch against Grasshopper and WARL.
The agency will initially be responsible for harnessing the company's database of customers with an email-based campaign highlighting future releases and current games.
The agency may also be handed as yet undisclosed future online projects.
EA, which was launched in 1982, has grown from a home computing game publisher to become the world's eight largest software company and one of the world's largest third-party publishers.
EA is well-known for its sports games under the EA Sports label, as well as games based on movie franchises and long-running series such as 'Need for Speed' and 'Burnout'. In May 2008, the company reported net annual revenue of $4.02bn (£2.03bn).