XenSource: a virtual unknown?

Even though Xen, virtual machine software for industry standard systems, is well known, The company behind this software, XenSource, is not as well known.

XenSource, with the help of the open source community, has developed software that securely juggle multiple virtual machines, each running its own operating environment, on a single physical system and produce close-to-native-machine performance. Xen is open source, and is released under terms of the General Public License from the Free Software Foundation

Although Xen is rapidly becoming pervasive in the world of Linux, people don't make a connection with XenSource.  If I asked 20 people at any random Linux conference to tell me about Xen, they'd certainly be able to answer. If I asked the same people who developed and supports this software, I'd surely hear answers ranging from Novell to Red Hat to IBM. It would be unlikely that I'd hear the name "XenSource."

Why do you suppose that's the case today?  What marketing, public relations or other steps could the company take that would equate Xen with XenSource rather than leading people to think about Novell, Red Hat or some other company that is using the open source version of Xen as the foundation for their product or services?