New York – Global advertising spending in measured media is forecast to grow by 5.1 percent this year, according to analyst GroupM, down from its initial forecast of 6.3 percent late last year. In 2011, ad spending reached US$482 billion, up by 5 percent from 2010’s $459 billion, according to GroupM. The research firm also predicted that annual global ad spending in 2013 will increase by 5.3 percent to $533.2 billion. For the U.S. market, ad investment in measured media is expected … [Read more...] about Global ad spending seen to grow 5.1% in 2012