I share the bullish opinion with you, and I have to say that the next 26 months for me will be waiting for STEEM to do what it was build to do. Then, if in 26 months STEEM, for some crazy reason, we would still have 1-2 million users, I would start to consider quitting, because it probably meant that a better project would have killed us and our ambition.
But I´m not seeing anyone or anything being able to stop STEEM, so I would say that hundreds of millions users, as you putted, will be achieved much earlier than 36 months... just my opinion!