Quality score is the biggest (and worst IMO) Adwords news in the last months. I was "playing" with adsense arbitrage with really good results, but now i try every kind of optimization and arbitrage doesn't work more for me... Post your experience. Someone can still make this ?
It's still possible if you have a well-ranked site of the same topic as you are promoting. It was easy money while it lasted, would've felt weird to live on such a thing for the rest of my life... I guess making money on the web is a bit like gold mining. Anyone can get stuck in with a pick and look for the easy income, but gold-rushes don't usually last long. But anyone who builds a drinking establishment where the gold digging is happening, hires staff, is friendly with everybody, provides entertainment, serves food -they make much better money than the average gold-digger.