According the the Wall Street Journal RIM is shopping for a mobile advertising network. RIM apparently has had meetings with mobile ad network Millennial Media about a potential buy, but have since stopped due to the value of Millennial. Popular ad markets AdMob and Quattro Wireless have talked to RIM but asked between $400 million to $500 million and RIM has been unwilling to pay that. Now, though, RIM is behind, as Google Inc. and Apple Inc. purchased AdMob and Quattro and have had great success.