There are a lot of these mowers out there. A local college has one (I forget the brand) but it autonomously mows dozens of acres of lawn. When I googled it last year, the company was only leasing the machines. I guess mowing by subscription is the way to go....
I've begun seeing them at some of my local golf courses, too. They're an obvious alternative to paying a crew to mow the rough, although I don't think they'll ever entirely replace humans for the fiddly detail bits (fairways and greens).