I heard about steemit somewhere online in a podcast about bitcoin mining. Someone started talking about altcoins and mentioned a social network called steemit based on a new coin and something about rewards for users.

I've brought some friends to steemit but not all of them are using it actively. I tried not to make a big conversation about the rewards so that they wouldn't arrive with the expectations of making "easy money". I focused more on the good content and nice vibe among users with common interests. None of them quit but I think the retention is an important issue to be aware of.
The offline interaction is something I think may be distinctive and successful on the long run but what I think might have an immediate impact is the card. I know there are lots of cards around and most of us have BTC cards but we "early steemians" would be very proud to walk around with our "SteemCard".