I've held twitter when they were at $15.
It's been a long time coming, but I think we will see some growth in the next 5 or so years.
Personally I see a drift from family and friends using less FB and more Twitter. This might be down to recent trends in geopolitical events where Twitter has been fantastic at broadcasting news as it happens.
Where as FB has slowly become a mine field of adverts and junk. This is now reflected in a decrease in time spent by users.
I'm sticking with Twitter! :-)