Many Germans who have a greencard have left and went back....not sure if they got their greencards through the lottery.
I know a couple who lives behind me who just became citizens and came here on DV lottery greencards with nothing. Slept on the floor and started to clean floors. That was years ago and now they have decent jobs, speak English very well and are proud to be here, but worked very hard to get where they are right now. But also lost a lot of their money due to the housing crisis and they don't believe they will be able to recover since their loss is huge and they bought the wrong types of properties.