I have an interesting story to report about "unlimited" space which we were offered by a certain hosting company- obviously I can't name them, let's just say they begin with W.
Basically they offered unlimited space, and when we actually dared to start using it for any major image or video content (okay so there was about 1Gb but they explicitly offered "unlimited") they deleted the content- oh and the site that housed it- without warning, suspended the entire account and wouldn't restore the site or apologise...
Needless to say we're in the process of migrating everything we have with them (thankfully not much) away.
Bizarrely when I spoke to one of their 1st-line support drones, he admitted that "yes it was unlimited" but "we couldn't use it for files".
Go figure!