Obviously you can build test suites for each of these scenarios, but I think it would be expensive to run all of them. That's all I'm really saying, it's by no means a bad idea, I think it's a great idea, just going to require some upfront thought of what type of environment the software is going to run in.

So it's expensive b/c it consumes CPU and time on shared systems, and those cost money... so I think a service like this could potentially cost significantly more to operate than say travis-ci.