I was watching the Bloomberg clip on Verge and the main topic of discussions was why Twitter is stuck at 300M users, and how come they've had a Billion signup & never come back (bounce-adoption rate?).
Here's my TODO list for Jack Dorsey —
Simple Signup
Think 'KISS', or better known as 'Keep It Simple Stupid'. It's not rocket science. Signing up right now is far too long-winded, and rather than having users pick those to follow at signup, give them an auto-populated list from the 'verified' accounts list.
Show new users the value of Twitter
Lot of non-techies have no clue what twitter is, or its value. I personally use it as a news-source, and many do. Perhaps give new users an insight into this upon sign up.
Twitter needs Chirps - long tweets.
That 140-char limit will hurt your user base. Something to chew on. Long DMs alone won't help.
Mac client is pants.
Have you checked when the last build was released for the Mac client in the App store? October 2014. Yes, they are proactively procrastinating there.
You need active development on your mobile apps.
Well, this is just the start. Over to you Jack.