I learned about DigitalOcean from advertisements. I saw the ad, read the site, and their advertising convinced me to try them. They were much newer at the time so I didn't have anything else to go on and never heard of them before. To me, for my preferences, DO is a strong competitor to Linode but what kept me from moving my important projects to DigitalOcean was the reputation of the Linode brand. So its hard to separate the advertising from other information from other sources.
Apple's "it just works" campaign led to me getting my first Mac. I identified with the issues they brought up in the ads, switched, and found out I really did like Macs better. Now, Macs aren't without their own set of problems so when it comes to what would make me choose a Mac over a Windows PC, those intangible, marketing-speak little things is what gets me.
A lot of people try to act like they're above all that but I can't believe that. I know we all hate to think we're swayed by advertising because we want to protect our individuality. I feel like I can still be an individual even if I buy into some marketing.
I also tend to buy brands that spend less on advertizing because they end up as a better deal for your money.
My point is that I don't relate to the stress that people feel from advertising. I'm definitely swayed by it but only when it lines up with a real desire I have. The desire comes first and the advertising shows me the way toward fulfilling it. It doesn't both create and satisfy my desires. Well, not always. For example, after I saw iOS 7 I totally wanted it. Luckily I will but if I had to pay for it I might. Now, I'm wondering - did the advertising create the desire for that or did I just see something I liked and it happened to be a good match? Is there always a difference?
Your point about product discovery is well-taken. In the case of discovery of new product types, it seems to be a valid issue. For product types that a person already has knowledge of, however, I would think it would be preferable to skip the ads and simply compare reviews. In other words, if I'm searching for a hammer, looking at ads for hammers will not give me the best information.
I do wonder if there are other ways to enable product discovery besides paid placement, but I'm not sure.