eCommerce and waiting lists

Summary

The behavior of an enrollment with eCommerce attached and a waiting list

Content

I have an enrollment that has ecommerce attached to it and it has a limited session size but I would like a waiting list (just in case someone would cancel). What will the expected behavior be? If memory serves me right, when the enrollment reaches it's set number the Learn Center kicks back an error message to the User. It doesn't acknowledge the waiting list at all. Also, the error message is confusing to the User. Does anyone else have experience with using ecommerce in this way?