ZenithOptimedia has released a new forecast of global ad spending, predicting a 4.3 percent increase in 2012 compared to 2011, reaching $502 billion by year's end. This is a slight downgrade from the company's earlier prediction of 4.8 percent growth. ZenithOptimedia still predicts 5.3 percent growth in 2013 and 6.1 percent growth in 2014.

The ad market slowed in April and May as advertisers became more cautious about the state of the global economy, partly due to economic troubles in Greece and the rest of Europe. However, with the Euro 2012 soccer championship underway and the Summer Olympics and U.S. Presidential election on the horizon, an ad boost is on the way. These events are expected to add a combined $6.3 billion to the global ad market.

Looking at radio, ZenithOptimedia expects "slight increases" in Network Radio of three percent this year, then two percent in 2013 and one percent in 2014. The report notes that "Radio continues to be the choice medium of retailers, seasonal products and automotive, providing heavy frequency and drive to retail messages. Spring and Summer bring key sporting events, which generate strong listener interest in baseball, college football and NFL."