Diablo Immortal also, in the simplest D2R Items terms, takes directly from an "feeding" method that many Japanese, Korean, and Chinese mobile games have adopted for more than 10 years. "Feeding" entails raising the attributes, stats or rarity of an item through having a duplicate of the drop. These duplicates are then fed to an item of the same rarity to increase the overall stats of said item. In general there are five copies as the industry norm to max out a character or item.

My first introduction to "feeding" was in Fate/Grand Order, which was originally out from Japan in July 2015 and made a profit of $4 billion dollars around the world in 2019. In order to create the most memorable character it can be, I needed to obtain copies of every one. If a certain campaign came around I paid around 300 euros to purchase the 5-star character I'd coveted since a long time. But I didn't get the identical copies I needed to fully appreciate this character's full potential. The rates for the most popular 5-star characters currently averaged at around 1.1%, it's no surprise that I didn't manage to get a copy of the character while enjoying the game (which I've since removed). At the time of writing, Fate/Grand Order was the seventh highest-grossing mobile game of all time, putting it ahead of Konami's Puzzle & Dragons, which also, I'm guessing, is also a gacha game.

In a GDC 2021 presentation, Genshin Impact developer Hoyoverse (previously Mihoyo) outright admitted that the process of creating characters was to generate the highest amount of money from its audiences. For example, the Raiden Shogun and Kokomi characters reruns that took place d2r items for sale in March 2022 alone brought the company more than $33 million in revenue.