Creative math FTL
Anyone who has ever looked at Amazon's Amazon Prime catalog and wondered where the 17,000 movies and TV shows it boast about are has probably experienced disappointment at the juiced up claims. It appears that the way Amazon comes by that huge number of streaming TV shows and movies is by counting each episode of a TV series as an individual show.
That means that something like X-Files that ran for many years and has roughly 200 episodes would be 200 individual shows in Amazon's mind. Fast Company says that the real numbers add up to 1745 movies in 150 TV series. 17,000 sounds a lot better in marketing.