Anecdata: My mouse is connected to my PC in the front, so I just reached to check the logo and I'm feeling a logo on both sides of the connector. So I unplug it to check and it has the USB logo on the top and the Genius logo on the bottom. C'est génial! <facepalm>

Wow. Indeed. Just dug up a wired mouse out of a junk box, and sure enough - Genius logo embossed on the lower side of the connector.

Many of the slots are vertical, i.e on desktops, so it’s a nearly pointless fact anyway.