An open-source, federated, and privacy-protecting alternative to the dominant advertising services. Something that gives the individual web user full control of which ads they see; from which indies, organizations, companies or any other groups. And where they can also filter ads based on clear categories, values, or tags, rather than everything being dictated by algorithms and "relevancy".
I actually didn't think about it much, because I block all ads. But consumerism can be fun, I wouldn't mind ads if I had a say in which I see.
Weird how neolibs are proponents of the free market all the time, but at the same time insist on shoving crap we don't want down our throats. I like your suggestion.