Are people building GEO tools? (SEO for AI search)

something that's been kind of on my mind, Exa Labs + Perplexity have been the biggest AI native search engines that I've seen and used, but how do they figure out what sources to use to show the user?

found out this was called GEO (Generative Engine Optimization) and there's agencies that help you get your content to the top of AI search engines.

But how does this stuff even work? And what is the market for saas tools in GEO?

Interested to see how this market turns out but i'd love to know if anyone has seen some cool tools that people are building in that space.