Game Of Thrones is one of those shows that has only grown in popularity as time's gone by, with a marked increased in viewership from season to season. The first settled on about 2.5 million per episode, but by the fourth that had almost trebled to an average of almost 7 million. The height of this (and thus the whole show), was Mockingbird, the seventh episode of the season. It's a strange one to get the highest ratings - compared to The Laws Of Gods And Men (Tyrion's trial by jury) and The Mountain And The Viper (Tyrion's trial by combat) either side of it, it's a rather slow-moving hour. Clearly the tense ending of the previous episode ("I demand a trial by combat") got a lot of people involved.