The momentum just keeps building for Millennial Media. The company is helping Interpublic Group’s ID Media bring its advertisers into mobile, the company announced today.

It’s a first-of-its-kind deal for Millennial, and while significant for the company, the deal also says something about the maturity of mobile advertising in general, said Eric Eller, senior vice president, products and marketing. The partnership involves 70 ID Media clients.

Millennial Media will help advise the advertisers and create and manage their direct-response campaigns, optimized for mobile, over its MBrand and Decktrade mobile ad networks.