The business has proved to be highly 'lucrative'.
a 'lucrative' career/contract
a 'lucrative' job/investment
(..) I guess Gru must just have one that looks exactly like it! What the... Those girls sold me cookies! Do you have any idea how lucrative this moon heist could be? I give you the opportunity of a lifetime, and you just blow it! - No, I didn't. - Oh, really? (..)2010 Despicable Me