Funny story, I once looked for a magnifying lamp for a friend online. Until I deleted the right cookie ads for this lamp kept appearing. The same thing happened to me with a ad for a kitchen faucet vendor.

The ads themselves were just mildly irritating as they were not for any personal product that I would have preferred that my interests be kept to myself.

However, from my own experiences I might be inclined to use some "private browser setting."

However, by using private browsing many of the cookies that we use for site features would be session only with the user's experience diminished on a return visit.

Conclusion: this bright idea by the ad networks has backfired and in the end will cost website operators.