I think this covers how it's supposed to work, but the reality is far messier and worse. In particular, the hypothetical cheese grater manufacturer would probably be have to pay Google to advertise on their own brand name adword so a generic competitor doesn't steal customers that already know about their great cheese graters. Oh, and about 90% of the people who see your cheese grater ads would be people who just bought one of your cheese graters. Even worse, cheesegraterreviews.com would be paid off by your (larger) competitors to review their cheese graters better and this site has much better SEO than forums.graterenthusiasts.com so they would list higher in organic cheese grater search.

All of this is to say that targeted advertising for niche, high-quality brands is only viable (at least if you're targeting someone like me) in an environment where search isn't beshitted by SEO, Google doesn't run a trademark protection racket, and reviews aren't 90% noise. Unfortunately, that's not the world we find ourselves in. At this point I'm more likely to just go to the kitchen store and physically examine cheese graters to find one I like than relying on the internet.