Promoting from one grade to the next is based on your Earnings Bonus, and your Contract Score from the past 30 days. The best way to finish contracts of your own grade (not an ULTRA Any-Grade coop), as fast as you can, ideally with a good team of players. Typically one must have 10T EB to qualify for Grade AAA, although this is quite uncommon as players of that level often cannot handle AAA Co-ops without a good team. Players can see their grade progress by tapping the egg in the top left of their screen, tapping the green 'CONTRACTS' tab, tapping 'VIEW OFFER' on any contract, and tapping on their grade on the top left.