Only 8% of the prisoners in US are in private facilities according to DoJ: http://www.bjs.gov/content/pub/pdf/p13.pdf -- where is your source for the claim that every prison is a "profit center" ?
http://www.nytimes.com/2013/08/25/magazine/what-a-tv-show-ca...
How that interacts with the costs of keeping them etc I don't have any feeling for