So one thing I do not understand, if one upgrades their level from say 2-3, is the extra income added to the new level's income, or is it lost? And if it's lost, do you get any credit towards the new level from the amount of lifetime left in the lower level?
a) It will be lost.
b) You get no credit.
OP / BTC-FlowHow and when are referrals paid out?
Thanks in advance

They automaticaly adds to your balance.