A few points.
1st: "Top 100 selling games right now, by revenue" by revenue would seem to give higher priced items like Steam Deck an advantage.
2nd: When I checked Steam Deck had dropped to #2, with Counter-Strike: Global Offensive at #1. Of course fluctuations are to be expected.
3rd: I'm seeing only 10% off, maybe it varies by location.
Question: Counter-Strike: Global Offensive is free to play. Is the revenue then from in game purchases?