Here&#x27;s irony for you: basic text messaging is almost free to the carriers, because it actually happens on the cellular protocol&#x27;s control channel. [1] Your phone maintains that connection persistently (I think), so fitting SMS messages into idle time makes it virtually free. The SMS cost is just a profit center for carriers, but this explanation also accounts for the speed of delivery, etc.<p>&gt; Look at what happens to iOS users trying to switch to Android: iMessage blocks their communication for months afterward.<p>It used to, but Apple built a &quot;deregister my number&quot; page that&#x27;ll be able to unlock that within a matter of minutes.<p>[1]: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Short_Message_Service#Initial_concept" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Short_Message_Service#Initial_...</a>