Granted paying Google at the start of the month is a pain...but frankly if you can domiante ppc...the world is your at your fingertips!!
Adsense is the best and easiest option to be honest but I prefer to sell advert space private as you can get alot more.
I love PPC with adwords because you can actually target only the people you like to receive your messages. Adsense is awesome for passive income, making money without doing a thing.
What do you all think about PPC versus PPV ? I've heard PPV can be much more lucrative as the investment cost is much lower.