why do i sometimes randomly get booster packs for no reason

[MrDeepDarkmind]

When I play a game that I like playing I have fun with it I get a booster packs.

No not the card drops since i can't get any card drops anymore but Booster packs drop randomly for games I like playing is there a reason why  or is it just random? 

[Bobsplosion]

I'm not sure if this is the official reason but here's why I think it happens.

 

There are 5 levels for each game, which require a decent amount of cards. Usually the drops you get don't even amount to a single level, which means you have to buy or trade for the rest. This means that each person is using more cards than is being produced.

 

I assume that once the cards reach a certain threshold, booster packs are distributed to put some cards back into the economy so people can keep leveling.

[Apo]

Once a badge is crafted for a game, it gives a booster pack to someone else who crafted the badge already. If you have a higher steam level, you have a higher chance for getting the pack. Not sure if badge level matters though.

 

Edit: I'm wrong see below

[Scott Bakula]

If a person has earned all card drops for a game, they then become eligible for random booster pack drops for the game, which are generated as players craft badges. For every 10 steam levels a person has, the chance of getting a booster increases.

 

To see what booster packs you can get, go to your badge page and click "View my booster pack eligibility".