Paid traffic and promoting SaaS?

Did anyone actually tried to promote any kinds of SaaS services with paid traffic, be it popups or push? Any experience/idea how would this convert? I think that might be pretty hard to "target", since its pretty niche offer? Not really GEO or OS related, how would someone optimise it?
Im talking about say AI writing content services like Jasper etc or SEO analizing/tracking (SEO Surfer), with reccuring revenue plans and so on.