The-Numbers.com has information about the 3rd Futurama Movie (Bender's Game) sales. According to them, Bender's Game has sold $2.16 millon in 2 weeks (thanks to Cx for the correction). The total number of DVD copies sold is 119,468, these values don't include Blu-Ray sales, so it could be kinda higher.

In the 1st week on sale, Bender's Game gathered $1.7 Millions (92,159 copies sold). Also, Keep in mind that there's already about $24 millions between the 3 first movies, hopefully, big numbers can open FOX eyes...
Don't forget to visit The-Numbers.com article over here.