A new paradigm in ISP services. Operating Systems and Networking technologies are not being used till it's design limits, with today's paradigm. MS Windows is not designed from the ground up to work with remote applications, or in the case it's possible, it burns a lot of bandwidth and costs a hell lot of money. Unix and the X-Window system are designed to take adventage of low bandwith and low memory conditions, or can be pushed to work on such conditions. And with a license as the GPL the inherent costs of Servicing Applications go down to zero.
Tutors can directly interact with the user's desktop and provide the required training.
They just can't do it, even if they wanted, because it increases the costs of support.