Logitech passes the one billion mouse

Logitech has annonced with pride that they has passed the mark of one billion mice sold since 1982 when they released their first product.
If we look closely, this device is certainly one of those that has least evolved. It has improved in ergonomics and accuracy, but the movements and clicks have managed to become universal.
One wonders what would have happened if the industry had been so fond of patents they are today, making any standardization almost impossible to establish without a costly long fight and uncertainty.