It was even better when they offered it self hosted (
http://www.interspire.com/). That was good! but they axed it in favour of the hosted version, boo them
I must admit though, they do push it, a lot. They try and get as many places to integrate with it which makes it's a good Magento alternative IMO
But if you use your own domain I wouldn't of though you got any benefit as you can't 301 it, you can only use a CNAME or change the NS.
Well that's how I understand it, my knowledge could be completely inferior here
