It's been interesting to watch this story unfold. Twitter is a broadcast system and therefore has many (useful [and not useful]) bots. These aren't users, but not all of them are spam. It's a simple counter-example to show that simple user (and engagement) counts will almost certainly be misleading. Twitter is in a big-time catch 22 with reporting here. It'll take skill to report a qualitative aspect like engagement with a quantitative metric (like they're expected to).
I've advertised on Twitter before and their engagement metrics are curious and a bit dishonest.
They measure any click on a tweet's body (not a hyperlink) as an engagement; where as an advertiser I define engagement as a favorite, retweet or reply.
Does advertising on Twitter work? I am curious if engagement matters too much provided Twitter is delivering the results? Of course if it is not cost effective then they have a problem.
It's not just "does it work?" but "what kind of customers are you getting?". Twitter seems more productive to me than any part of facebook, which seems to desire to ravenously consume one's life. It's only a slightly less consuming task than some online games (MMORPG).
You're purchasing time from people that are busy, and productive, and have a life that on the whole it not completely virtualized. Compare that with Facebook and MMPORGs of sorts, and there are some highly successful virtual people who live real lives in mobile homes and shitty apartment complexes. Not to say their overall quality of life is bad, but maybe their balance is off kilter some.
