When someone wants to cash in and out of Steem, the projects that make that the easiest will be the ones that separate themselves from the pack. People wish to have one-click buy Steem in their account and one-click cashout into their legacy fiat wallets (banks, PayPal).

This is hyper important, at least in this stage of the game. So many people are dissuaded from buying BTC through a fiat on ramp, then transferring to a altcoin exchange and then getting it here (or to any other place...). Remember, we are talking about the bulk of the population being highly computer illiterate. They can use email and web services, but all this crypto stuff is currently just too daunting (these are people that will have a simple password for their whole digital life).

A simple fiat on and off ramp would be THE killer app for STEEM...