Half of Google's income is derived from businesses pissing their marketing budget up a wall with incorrectly targeted ads. But it's still more effective than newspapers.
Ah yes I was waiting for a response like this. Adsense campaign or do you mean Adwords campaign? There's a pretty big difference between the two.
Also, what's the difference between pissing away money on "poor targeting" and "testing" targeting which helps you to determine what the best options are?
Alot of bro-vado in your comment - what's your avg CTR? Churn rate? Spend? Out of curiosity.
Or out of nowhere. I get ads for real estate in Chicago - except that I live across the Atlantic. Or ladies products every time after my fiancee used my phone.
Not to mention how most ads are just plain bad. I don't mind actually watching good ads - I was hooked onto buying the Asus Zenbook Pro Duo for a while because of its ad (although later I learnt that the product was shit). The Honda Day/Night ad is another one that comes to mind.
It makes sense to show ads for potato chips but with washing machines you should stop after purchase.
I much preferred the time when kiteboarding sites had static kiteboarding ads instead of the current situation where ads are totally out of context.