bwnbwn - 2:44 pm on Dec 3, 2013 (gmt 0)
"Topsy is one of the few firms to have access to Twitter's entire data stream."
I would say "had". I don't see twitter allowing this to continue without a nice sum from Apple.
I would suspect the audience being tracked in 30 and below. Leaves a very large segment of the population out of the loop.