I use Twitter mainly for the news, since Twitter enables me to get a much more complete picture of events compared to traditional media. But it took me a long time to really grasp that I could use Twitter in this way. Initially I just followed some work colleagues when I had to create a Twitter account as employee of a company I worked at. Otherwise I would have probably never created a Twitter account as I just didn't see the purpose.

I think one of the biggest challenges for Twitter is on-boarding new users.

With regards to the platform itself: it would be nice if Twitter would had some sort of article quoting mechanism. It's not uncommon to see a Tweet with text from an online article included as a picture. I also do this myself sometimes, since it seems to me people are more eager to click a link if they get a much better grasp the linked content and 140 characters is just too little for this purpose.