I've said this before, but I think it's worth repeating.  Growing the bitcoin economy is very simple.  Dedicate a portion of your earnings to buying bitcoin every week (however small that may be doesn't matter).  And never sell bitcoins on an exchange if you can possibly help it.  Instead, use those bitcoins to buy stuff (or pay people).  I think if everyone tried to do this, it would be the most effect way to grow bitcoin usage.  Trying to explicitly market bitcoin to people that may not know or care about it can backfire (but countering anti-bitcoin propaganda is important).