Really? At least for ads which track the click I am almost certain that I can say that I never have. I've been using AdBlock since the very early stages when it was available and even before I actively avoided clicking on ads. It might be that before AdBlock I would have seen ads about something so that my subconscious mind attributed the constant reminder about that product with some kind of quality (like TV ads). Then, once I had to buy a product which did what this one did I would more probably buy the one which I felt I knew already. But that is a negative thing about ads, not a positive.