This is a bit of a sea-change; the free IP messaging apps are starting to eat the telco's lunch.

The carrier's response is predictable - build faster networks and try to charge a premium but the upshot will be a simple commoditisation of the carriers, eating margins and marginalising these enormous players.

Unless the carriers become content players (as BT is attempting to do for example) or in some other way pivot to offer value added services, they are on a short road to irrelevance