When HF20 Velocity is released, account creation will no longer require delegation of Steem Power but a permanent minimum bandwidth. This was necessary to prevent automated abuse of the signup process which would give free Steem to attackers.

This is why Steem / Steemit has not grown faster because accounts had to be grown through a vetting process. I had suggested a witness referral program a few months back to bypass the issue, but it will be moot with HF20.

My understanding is that as of Jan 1, 2018, there are over 500K accounts and Steem is about $5. If it achieves the same level of Reddit which is over 200 million, we can extrapolate that Steem will be approximately 400x its current price. That would be $2000 per Steem.

Your estimation of $100 is on the conservative side. The question that remains is when...