What you do not know is the up front money it needs. 

Remember, they are leveraging existing infrastructure, sharing in the investment and it looks to me like Mint will likely make a management fee off of this as well.

Note the terms:  return, profit.  I'm sure they have planned this all very carefully and likely PBDAC has as well given their partnership.

You are right, we do not know, nor do you.  Just speculation, but I think I'm right on the bucks with this.