My Googling skills suck when it comes to finding anything that needs more than two search terms, but I finally found a couple-three reddit and Facebook sites with more details.
According to those (and we know how reliable they are
), Terrible writes the sponsorship checks, not Monster. It puts Monster on as part of a B2B deal, Terrible gets big discounts from Monster, and Monster gets preferential treatment in the stores. =IF= accurate, that explains why the money follows Riley - it's the family footing the bill, and Monster happens to be the long-term partner getting the free ride and bennies.
According to those (and we know how reliable they are