zarathustra2011 - 8:27 am on Aug 2, 2012 (gmt 0)
Google Adsense probably accounts for about 50% of my monthly income, but that is only because the other side of my business (totally non related to advertising) has plummeted this past year. My focus is primarily on the latter, and not on Adsense, because whilst I can't count on either, I feel Adsense alone would be too many eggs in one basket.
I think for anyone planning to give up the day job, have a plan B already implemented. If Adsense fails, at least you'll have a bit of a cushion to soften the blow.