OP suggested the CSP should give 0.1% of their revenue to open source software they make their revenue from. As Redis isn't the only SaaS AWS offers, I was gracious and allocated 10% of those 0.1% to it.
Got it. It would actually be less than that since the number you selected was for revenue, not profit which is what OP asked for. Looking at some prior years it looks like AWS profit is close to 1/4 their revenue, so $90 billion would leave them with (generously) $25 billion profit. 0.1% of that would be $25 million and 10% of that (your estimate of Redis's share) would be $2.5 million.