I mean a lot of the money of the groups come from Donors, the Mabanga System, tothe people who pay songs for them, but what about the album sales? Because from what I understood is that Album aren't that big of money making in Congo

original albums are not sold that much except donors  who'd for example buy 1000 cds and share to friends so they can hear the song of praise done for them. few people from the popular areas of kin can afford real cd's so they either buy fake ones or for 1 dollar or something like that you can have a flash disk with all the songs,which is why musicians put all their energy into donors and the mabanga money and the concerts especially a guy like koffi who refuses to lower both his cd price and the money he asks for to play a concert  to adjust to the situation
all in all,albums have success but sales wise its alllllllways uncertain,you'll for example hear like ingeta,soyons serieux,13 eme apotre to name a few reached 30000 cd sales pretty quick but they 1 year after you'll be wondering how come it still has not reached even the lowered golden disk number of 50000