Every text message you send through a marketing platform travels through a quiet supply chain of brokers, carriers, and regulators before it reaches a phone. Most senders never see this chain. They see a price per message and a delivery rate, and that's it. But the economics behind that single message explain why SMS to Germany costs five times what it costs to the United States, why some routes mysteriously stop converting, and why a "cheap" provider often isn't cheap at all. So who actually gets paid when you press send?