http://www.azroboticcleaner.com/ - My cleaning task can be done manually within hour. Thus, I was wondering is it worth to spend few hundreds to buy a robot vacuum cleaner. But, my friend was proved that it is efficient device by sending me a video showing her robot cleaner was doing cleaning job on floor and dust it have been collected. I then realized that there are invisible wee dusts only can be cleaned via vacuum. And, robot vacuum cleaner definitely is great helper as you do not need to carry vacuum machine while doing cleaning.