I will never by anything from an ad - by running an adblocker I am *helping* the site I am visiting by making their targeting more specific.
Someone paying $20 for an ad trying to sell me a product, will be happy that their ad is not served to me -I am not going to buy their product in the first place, their money is better spent advertizing to people who might buy it.
Me looking at an ad does not help sell any products.