Much of it isn't even that. A huge proportion are not even real humans but are instead accounts being operated by one of the myriad of pieces of software that enable automatic posting on behalf of a human.
Perhaps my view is skewed as we have a travel blog and know many other travel bloggers but a vanishingly small percentage are real humans actually typing their own tweets in real time.
Shazam [1], a company that makes an app to identify songs recorded through the microphone, makes money off of figuring out which songs get a lot of interest. Twitter can do something similar, if they don't already.
Everyone knows, that everyone knows, that its a very valuable dataset. But nobody is apparently interested in paying for it or otherwise monetizing it. Shades of "emperor has no clothes". The end result is Google Reader got cancelled.
If twitter was not standalone and was a mere subproject of a real company, it would likewise be long gone. They have no plan B so they'll have to keep doing what they're doing until they run out of money or are purchased, pretty much a Yahoo situation. Its like a decades old portapottie at a concert venue, everyone goes there does not mean its worth anything to anyone.
It would be a nice, cool world to live in where sentiment analysis is a thing. Its such an obvious and tasty idea, that unfortunately is completely wrong.
1. As another user mentioned, more tweets are from bots.
2. Lots of sarcasm and rhetorical questions in tweets.
3. Nobody tweets about their hemorrhoids. Or abortion. Unless you're GoPro, good luck finding insights.
There's an informal support group that tweets about perinatal depression, OCD, and psychosis. This includes people who've taken the choice to have abortion (or even sterilisation) rather than go through what they went through before. ((Watch out, this is just an informal group and there's not much in the way of clinical or data governance.))
Here's a british men's health magazine advertising itself with advice about hemorrhoid prevention: https://twitter.com/MensHealthMag/status/752076400102895616
I pretty much only tweet about treatment for mental illness.
I'm not sure how useful this kind of stuff is to other people.