Quote Originally Posted by DrunkMonkGar View Post
If I have you right, those sacks are global multipliers. You get them when all of your cookie makers reach that threshold. (ie: 25, 50, 100....)

I've been focusing on reindeer and uping everything else when it cost less than the next 100 deer or deer upgrade.
You get another global multiplier when every item reaches another 100 levels, at the same time. The limiting factor are mostly the boxes. I've only ever been able to get the boxes to 16, at the highest.