The bulk of the sets are still in the U.S., where HD content continues to expand. Nielsen recently projected that about 77 million homes have an HD set, up 20% from a year ago.
This year worldwide, 34 million homes will add an HD set, according to Informa.
The company suggests that free over-the-air broadcasters in certain countries are increasingly offering HD feeds of sports events, such as the Olympics and World Cup. This is critical, because broad penetration will only occur when the free broadcasters offer HD content, as they do widely in the U.S.
Informa notes that massive growth has occurred since 2005, and by the end of 2016, it predicts that many countries will be nearing a point when most homes will be heavy HD consumers. That could bring a round of upgrades to an "UltraHD" model.