I wonder if they are including in that the money they already invested in the Ahrefs SEO tools. It seems to me that their SEO tools were already crawling a lot of content so this may be an extension of that / a new way to monetize the data. I personally know a lot of people who pay for their SEO tools so I imagine they have a decent amount of revenue.

downside: doesn't seem to care much for boolean ("-keyword") search terms, instead opting for the modern thing of "let's actually search for that keyword, too!" v______v