One of the important points about Nxt (that a load of people still don't get) is that Nxt is designed, not only as a crypto-currency, but also a toolkit to  to allow people to build stuff on a crypto blockchain.
It's the third party, targeted applications that will get the mainstream involved in crypto, not the hassle of downloading their own blockchains and setting up nodes.

For example:
Nxtty: messenger service based on and funded by Nxt.
https://www.facebook.com/pages/Nxtty/645168825569486

Secure AE: The Nxt Asset Exchange in your browser, no client needed. Also implemented a simplified form of Smart Contracts a few weeks ago.....
http://www.secureae.com/

FreeMarket: de-centralised, anonymous marketplace running over the Nxt blockchain. (This isn't quite as simple, but it is cool)
http://nxtfreemarket.com/

and there's more coming up. This is how to get to the mainstream, guys, take note.
Not everyone is ready to jump into the world of crypto-currency, but pretty much everyone is happy to use a good messenger app or a marketplace.