1947
As if it wasn't bad enough that they want me to use a random internet service to add a keyboard to a usb wifi receiver, they have the balls to put this for Firefox users. I clicked out of pure curiosity, as I'm not even remotely interested in involving a corporate internet service in getting my keyboard connected to my computer. This is the message you get now on Logi Options software if you have a Unifying Receiver: 
For the curious: https://logiwebconnect.com
EDIT: some people on the thread have brought up that the error message being displayed for Firefox users is due to the WebUSB API not being implemented by Firefox due to security concerns. This still does not justify having to use a web app to plug peripherals to a PC.
Logitech has been making atrociously shitty fucking internet based software for pretty decent hardware since the first harmony remote back in 2001. Only buy their hardware if it absolutely will never require software of any kind imo
Every Logitech mouse and keyboard I bought broke in some way, their hardware is just as bad.
I've had a cheap Logitech Marathon M705 mouse for a long time and it's been fine. Batteries (2 x AA) last around 2.5 years for me.
Every mouse I bought started double clicking within a few months, the keyboard keys started falling apart and the RGB LEDs started to fail. Moved on to a custom keyboard and a glorious mouse and haven't had a problem in 4-5 years.