Brush 256 every day, keep 1000u in the account, basically after about 10 days the next airdrop will come to you, then continue brushing every day, expect a loss of 10-15u per month, and you won't lose with an airdrop once a month. It's slightly higher than investment management. Create a few more accounts, the bonus period will probably last a month or two. Later on, there might be some rules to counteract the profit. After all, the studio is making too much money.