While I'm not exactly zukaus, I will try to reason this through. The Pokemon franchise has sold over 150 million games worldwide. Let's say about 1/2 of these games are handheld RPGs (though it is probably more). If you divide this amount equally among the previous three generations, that means at least 25 millions copies were sold each generation, even with a little leeway. So I think that these games will sell at least 20 million combined.
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