Perhaps they do provide $9/hr of value but they are only compensated 7.25 and someone higher up in the company gets that other 1.75
If I can get people to deliver $9 of value for $7.25 then I deserve at least part of that $1.75.
Just realised, the person who found me my contract gets £50 per hour just for finding me this position. That's the market value of getting me into this position, my client are happy to pay it, and its worth it to me to work here despite losing out on this money. Same deal.