Magical Tip Jar increases when you buy upgrades, structures, and cookies. It has a base capacity of 500,000 Rainbow Cookies. Every time you open it for $2.99 USD, the jar resets to 0 and start filling up again. You also get an increase of 500 on your free pack of rainbow cookies.
Tip Jar Bonus Edit
The more often you open, the bigger your Bonus!
Each time you open the jar, you'll get +10% bonus amount of Rainbow Cookies the next time you open it.
In Version 4, there can be limited amount of cookies inside the jar, starting at 80,000. This is later increased.