Twitter definitely does not have millions of daily active users. There are only 824M total tweets. Comparing IDs from posts 24 hours apart shows there were ~500,000 tweets in the past 24 hours.
I didn't say "millions", I said "a million". That's according to their own reports, and if there's 500'000 tweets, it's quite likely there's a million people sitting there with a tweeter client open (not everyone tweets every day).
