Right now the barrier to entry (in tech skills) are very high. So yes, in many aspect advertising is ineffective.
But with a mobile wallet for example we can start to do some very cool stuff. For example, Facebook advertising
for RSVP in meetups in Argentina is really working well. The people who show up are guided through step by step on how to
setup a wallet, fund it and trade.
fav-desu is doing really cool "giveaways" that bring in new users everytime he does one. I promoted the BitShares 101 ebook to everyone who has an interest in bitcoin on Facebook and I've hit the bell curve where now, it's not as effective anymore. (Email list of about 300 now)
After many different test, I decided to hold my funds for Meetups and Product launches (moonstone, limewallet, etc)
I suggest looking into http://faucet.bitshares.org/refscoreboard
to see which affiliate are bringing in users if you are curious.
Press Releases should be done yet we do not have someone to write them now. (I'm french and PR needs perfect syntax/grammar)
Every Press Releases cost at least $300. But with that we can hit bloomsberg, techcrunch, etc.