Yup, the oft-quoted figure of 44 million sales, it transpires, refers to the United States and Canada alone, not a worldwide figure. This is surprising news and since it comes straight from the horse's mouth (in this case Tom Doherty's, the head of Tor Books), must be taken as fact. Given the normal ratio of North American sales to the rest of the world is about half of the total sales, that should put worldwide sales of Wheel of Time in the region of 80-90 million. Which is a lot, and considerably more than previously thought.
There's some interesting stuff in the rest of the video (which includes soundbites from Brandon Sanderson and Pat Rothfuss), although I think we can take the claim that 'lots happens on every single page' as a slight exaggeration of the amount of incident in the late-middle volumes of the series.
For comparison's sake, worldwide sales of A Song of Ice and Fire are closing rapidly on 20 million (of considerably fewer books) worldwide, whilst Terry Pratchett's Discworld series (which has considerably more) recently passed 70 million.