Mostly I think ads, are wasted on me.... not saying Im immune or something, but I rarely think they actually make a differnce.
Product reviews... if you want to buy something, today its easy to go read a review (or watch) of X product.
Sometimes if the product review is very postive, and you really do wanna go get X product.... it ll be the last little thing that throws you over the top, and go you buy it. Esp if its a thing on sale too, its like nows a good time to buy it, and this review was very positive... done.
With video games, I think gameplay videos is a much better "sale" effect than just a poster or such.
As others said, a ad is more like a "reminder" that something is soon out.
I dont buy something before I see actual gameplay these days though.
Have to watch it, and think, this looks well done, or could be fun.