... insightful stuff ...
I wish this thread was not in the Lounge, so I could +1 both of those posts, couldn't agree more.
Also, I think it's easy to think "oh marketing... that means I need to buy lots of ads all over the place right?", but that is both a very expensive way, and not really doing that much.
Marketing is so much more then that. Basically it's every time you ever talk about your game to anyone else. And every time anyone else is talking about your game. (hopefully in a positive way)
For our game Touchgrind BMX, we actually won 100k euro in TV ads on a german television channel.
Didn't notice even the slightest bump in sales...
It's much more efficient to get people to talk about it, and get exited about showing it to their friends.
To help our players do that, we added the possibility to upload replays to youtube.
We had thousands of them uploaded within days of launch, and I do not doubt it significantly contributed to the success of that game.
Another way, often used by Indie devs, is to get a following on forums, and even set up your own forum just to enable your fans to talk about the game.
It both helps to market it, and provides valuable input, and a horde of unpaid testers (of course, the quality is lower then payed testers, but the numbers of them can be really helpful)