[MichaelGG]

Actually, most carriers aggressively turn down customers that send dialer traffic, due to increased overhead versus total minutes (most dialer calls go unanswered or last only a couple seconds). Carriers would LOVE a magical way to distinguish, in real-time, a dialer call from non-dialer. But since they can appear from any number to any number, there's no way to know.

Instead, the carriers look at aggregate stats, and if it's too bad, they raise rates, charge fines, or disconnect customers. Some companies take a hard line and just cut any customer off if they appear to have any dialer. Others don't want to throw away an entire customer for only one fraction of the traffic. So everyone dances this line, trying to jam as much dialer in as they can get away with.