[usr1106]

That's a major difference between the US and the rest of the world.

In the US the recepient of a mobile call and obviously also an SMS pays. Either per use or as part of a package.

In the rest of the world the recepient pays absolutely nothing, the orginator pays either per use or by package.

So such gateways make sense for US-providers. But no sense in the rest of the world. Very few did always exist during the last 20 years even in the rest of the world. I tried to use them years ago and failure rate was something like 90% or more. If something is too good to be true it's typically not true.