> You would need to penalize any website that accepts money from users. There are a lot of SaaS companies out there writing blog spam to promote subscription products.
I don't see that as a problem, because blog-spam without advertisements is going to get down-ranked until it is exactly where it needs to be. If a single site dominates too much, then a hard cap on how how often a specific site can appear in the results is feasible, or weighing each page with a percentage of all the pages on a site (thereby penalising sites that have millions of pages). Specific exceptions can be made for wikipedia, or similar.
For example, lets look at digital-ocean: Is that constant blogging something that users find helpful? Well, if a page is relevant to the search term then there's no problem. If it's not then the numbers of 'irrelevant to this search' feedback from logged-in users will gradually down-vote it until it is correctly ranked. If it's relevant but is one of 30k pages on the site that matches relevancy with that search term then it gets down-ranked.
Basically, the motivation to do nothing but spam is completely eliminated. People spamming "How to do $TRIVIAL-THING" to drive engagement with their SaaS product is, I feel, a completely valid result if the search term matches relevancy with the specific blog post, and the site isn't doing a barrage of postings.
Humans respond to incentives. Taking away the incentive to generate endless drivel and replacing it with the incentive to provide good content is the intention behind my proposal.