New York, NY, [April 11, 2007] - Interpublic (NYSE: IPG) announced today that it has agreed
to acquire Reprise Media, Inc. a leading provider of search engine marketing (SEM) solutions and the largest independent SEM firm in the United States. Reprise Media is known for its leading edge technology and its ability to use search as the central point for integrated, cross channel marketing programs. As part of Interpublic’s recently created Futures Marketing Group, Reprise Media will remain a stand-alone unit that will partner with agencies throughout the holding company as well as seek out its own clients. Reprise Media will continue to be led by its
founders and Managing Partners, Peter Hershberg and Joshua Stylman. Terms of the transaction are not being disclosed.

Press release here.

I am wondering, in what sense Reprise Media is the largest SEM firm in the US?