maybe this is true for you personally, but I don't think it holds in general. most of the time ads are completely useless (and I personally run ad blockers on every device I control) but every once in a while I see an ad for something useful I just wasn't aware of.
for example, I recently saw an ad for an electric hot plate that can keep a mug of coffee warm indefinitely. at first I thought it looked like a piece of trash, but then I thought what the hell, it's $10 and my coffee often gets cold before I finish drinking it. it turns out that piece of trash keeps coffee at pretty much the ideal temperature for drinking. I have gotten well over $10 worth of enjoyment from the thing and I would never have thought to purchase it if I hadn't seen the ad.