izzyvideo.com (showcase 'customer' on this website) does NOT use WPMUdev

One of the 'showcase' websites given is izzyvideo.com
This website says that if you want a membership website like izzyvideo.com, then you should buy the plugin - it's even featured in the video sales pitch

One would assume therefore that izzyvideo.com AND the other showcased website used the WPMUdev plugin??
The fact that you don't say this website uses the plugin or not doesn't matter - people like me will assume that izzyvideo.com is a happy paying customer

I emailed Izzy - he says he has never ever even heard of this website, let alone used the plugin

What am I missing here?

My experience with trying to get the membership plugin to work + izzyvideo.com is now getting me worried : (

Some sort of reply would be great

Omar