That was a big game changer for me too! And prosperous and rich world seems to count a lot in score (plus the fact that you have high happiness), though the highest cashflow gap is between unstatisfied and satisfied world, you better take care of each world you colonize!
On a side note, I've never seen prosperous or rich tourism/luwury world (because they don't supply anything). I tend to rely on them a lot at first, but after it seems that going for oversupplied worlds gave me good amount of money and happiness, plus I still had more resources to connect to other world that way...
Can't resist to publish that pic... Didn't even need fancy tech as infraspace or starbirth... I'll stop playing now ('til PC version!)
