Yep we can all argue till we're blue in the face about whether Google has a monopoly on our earnings but I for one rely on it heavily and don't mind admitting it.
I'm sure they'll be some of you screaming at your screens saying WELL DON'T RELY ON IT THEN but no matter what strategy you take - list building, forum posting, social networking blah blah blah you will still have relied on Google at some point to get your traffic, I guarantee!
So I recently setup and adwords account and you know what... I reckon it's cheaper than paying for SEO, plus my website doesn't get penalised or hit by negative SEO either.
Neither do I have to spend hours/days/weeks/months/years writing articles like I've done that were good articles but have pretty much counted for nothing or posting genuine useful answers on forums only to be banned because I put something wrong in my signature or creating squidoo lenses/hubpages that never get found...need I go on.
To sum up, Google Adwords is better than SEO.