so the "intended" way to play is to get 11000 fans in 100 days. and the only way to get fans is to buy more cards. means the starbits procured by millionaire mission is not to be earned but must be spend to buy more cards. everytime you do the mission, make sure to buy a card that have 100+ fans to cover the cost.

so the next question is, is it BASE fan or current fans we have? (boosted fans).
and for one who wonder about the roi, maybe the time extended almost double depends on the market price of the cards used to cover the 100 fans / use cost.