In theory, the private prison business model calls for corporations to build their own prison infrastructure, then bid on prisoners, offering to take them from the public system for less than it would cost to keep them. In exchange, government had to make sure private prisons were kept full, in order to maintain their profit margin. Deals were structured such that if government didn’t deliver its ‘quota’ of inmates, it would have to pay the full negotiated price anyway. This incentivized both government and these private corporations to create enough ‘product’ (in the form of prisoners) to make it financially worthwhile.