Funnily enough this kind of advertising has an adverse effect on me: Showcasing your product as sponsored content at the top of the search results at Amazon, as well as Google or the App Store, suggests that this is a subpar product that needs to pay to be relevant. I’m not sure how common this attitude is, but by now I subconsciously ignore these ads.
Of course there are also brands and products I know and like, which appear in these ads, but I see them as an exception, as a shining pearl in a sea of mediocrity, and continue to regard sponsored content as a strong indicator for lacking quality.
Isn't this similar to what Amazon Marketplace does? Of course, they do allow advertisers to promote their stuff, but apart from a top few sponsored content, rest all are ranked by reviews (or so they say).