It would only perform well if you identified some actual source of latent demand. For example, maybe many people searching for Taylor Swift concert tickets would actually be happy with movie tickets to see a simulcast. At which point, you are providing real information to some searchers.
We can debate and disagree about whether this is something you want in your search results, but it’s not spam. Spam exists because it doesn’t have to compete in an auction.
Or exploited some addiction.
Maybe hurricane care insurance would have a high CTR even though it sucks. Maybe impulse purchases would have high CTR.
People choose to do lots of anti-user things (eg, sugar sodas and diabetes, cigarettes, 9 year car loans at 14%, etc). Enabling bad things is a bad thing.