Typically I use http://example.com for this purpose.

Interestingly, your linked URL does use SSL, and despite NeverSSL's description page insisting the contrary, they are.

And it took a little jiggling to get back to unencrypted, http-only mode, which is still working, but yes, it looks like they're redirecting to some unique, rotating third-level domain label.

I would assume it's a dodge for browser software that's trying to defeat, block, or bypass the unencrypted connection. Such as a reputation-based or blackholing system. It would be bad if standard tools tried to block us from pages of such utility, wouldn't it?