In addition to popularity, I think we need to address how 'easy' it is for non-Bitcoin type people to invest in the coin. Even though the site will likely become extremely popular, the group of investors is still pretty much limited to crypto-currency traders.

https://steemit.com/steem/@timcliff/important-steep-learning-curve-discourages-steem-power-investment-from-steemit-newcomers-seo-help-needed