Online ad networks are starting to get some traction. It’s hardly a mystery why: they give brand marketers a beeline to greater buying scale and a way to drive down CPMs. Even the biggest Web sites don’t have the reach of ad networks, according to a new report from eMarketer (per comScore). Google, viewed by 70% of U.S. Web users, scored just ninth on the list of top ad-supported media properties and ad networks in July. But the Google Ad Network placed third.
