Via Twitter, @Brandon_Postal shared a word cloud made of A Game of Thrones, which he noted showed quite how significant Jon was ... or at least the word; we rather suspect that many mentions of Jon Arryn added to the imbalance. The font size of individual words show their frequency, with the largest font size used for the most used word (that isn’t an article and other such things).
He provided further word-clouds for A Clash of Kings, A Storm of Swords, and A Feast for Crows, which shows word frequency in each of those novels.
This led me to wonder at a progression series, that could show the shifting prominence of certain characters or things based on frequency of mentions, starting with AGoT, then AGoT and ACoK, and so on until the last cloud covered all the novels published to date. He happily obliged: Books 1 and 2, Books 1 through 3, and A Song of Ice and Fire published to date. Some interesting data can be mined from it, if you stare at it long enough (Robert and Stannis are almost equally mentioned in the whole series, at this point), but it’s mostly some fun trivia.