Product placement for companies like snickers, to generate interest.

In game ads as a means to keep player just want to play more, these sometimes unskipable ads are often used for extra lives

Companies might license out to food companies like Kellog to make food of their games

Starting a trading card series, these cards could have in-game use.

Toys in kids meals

Continuous income, this can be used for ontinuous development

Battle-Pass, keeps players playing for longer

Expansion, to add to the story or end it.

Pre-order bonuses, or free content

New game modes or diffuculty options

immediate Revene

Pre-orders are a way for a companty to have a good estimate on how well a game will sale

Digital sale, save in the phyiscal cost it takes to make a ship a game, cuts out physical stores

Push notifactions, to remind players when there is a in-game promotions

In-game shop, for contined development

Tutorialize,and condtioning playerbase to get used to spending time in the cash shop