I'm going to start off by saying I think consumer debt in general is a cancer on society, and I've said that before but I'm going to look at this from the lender's side just for a moment.
The essence of this arrangement is that someone with horrible credit (let's say a score of 450) can buy a service and have their credit score raised. We don't know just how high at this point but let's assume 100 points. If we view the difference between how much he paid in ($4300) and the amount he got back ($1750) is the cost for him to "buy" a better credit score ($2550 and three years in total). To me, that's a high price and an inefficient method to improve one's credit score but it may very well accomplish just that. If he just left $4300 in his savings account he wouldn't have an improved credit score so he took a different path (again, not the one I would have chosen) but he did in theory get the product he wanted to purchase, a better credit score.
"Masked Bandit is a gateway drug for frugal spending." - Unknown303