To 'whale' in a game or 'whaling' is a term for gamers or gambling addicts who spend a good huge amount of money on video games or casinos. Since a whale is huge and they pay hugely for gambling or gaming, you can see why
this is a thing.
With gamers,
microtransactions existed for them within free-to play games (e.g. loot boxes, in-game currency, booster packs, cosmetics, etc.), gacha-like games,
mobile games, battle-royale games or anything along those lines.
Gamblers are people who whale tons of cash on slot machines, poker and other natures of casino games and gambling.
"Whales" was a phrase first used by video game publishers to describe their main customers who insufferably liked to gamble their money for in-game items.
Bob: "Hey, Dylan. Guess what happened: I convinced my mum to buy me V-bucks and I spent a heck load on Fartnite last night. So cool, dude."
Dylan: "That game is for toddlers. I see why you needed her to buy it for you. Because toddlers rely on their mummies, and you like to whale money within a crappy game, to buy things you don't need. Player Ultimate Battlegrounds is way
better than your game."
Sarah: "Guys, guys, guys... come on.
It's not that bad. I spend my free time whaling my student funds on Weeb/Grand Order to get the best units with Gacha hatchers and to be a better player, haha...
I think I'm the worst than both of you combined."
