well this swiftlet farm require quite a lot of capital, my friend's dad involve in it and almost give him a sweat because the 1st few months did not has any bird flew it.
But after that thank god it slowly improved and bird nest getting more and more, the most successful in my area is the one in Segamat, which the abandoned tallest building in there, they are doing well at there, 1 month revenue around 6 figures if i'm not mistaken