Ford is among the brands running cross-media campaigns through AT&T's AdWorks network.
Google's network tops this list of the largest online ad sellers, ranked by reach.
Yahoo's network reaches more U.S. users than any other, according to comScore.
Tacoda CEO Curt Viebranz to head all ad network holdings and technologies; AOL headquarters moved to New York.

June 6, 2012
1:00pm ET / 10:00am PT