One of this fall's most hotly anticipated shows is back. Boardwalk Empire started its third season on Sunday, September 16th to much fanfare, and the success of the premiere was helped by a big outdoor advertising push from HBO.

The venerated cable channel utilized a wide variety of out-of-home media to promote the launch of new season, with subway posters, and bus exterior in New York. In Los Angeles the campaign could be found on a tall wall on the city's famous Sunset Strip, and on transit shelters and buses.

HBO recognized that outdoor advertising's advantage over other media types is its ubiquity. Television ads can only capture their audience's attention for their own duration, but out-of-home is an always-on medium, reaching potential viewers wherever they might be.

This season will see Steve Buscemi's Nucky Thompson, the uncrowned king ofAtlantic City, face some of his darkest days and some unexpected challenges from new characters. What will Nucky do? You'll have to tune in to find out.