Right, but I don’t think 100/mo is quite what is considered a whale.
Just as in casino gambling, where I believe the term came from, a whale is someone who throws a few hundred to several thousand into a game in a month, possibly in a large number of smaller transactions so they don’t even realize their running total. It’s the people for whom the “10’000 rubies for 49.99” in-app currency chests are meant for.