Cleaning Job : The most daunting task that's always in increased demand with advancement of civilization, as humans are reluctant to work on it.
That's where we really need a LOT of robots.
Romba did part of it. But cleaning job is tough. You need to differentiate between what's asset and what's junk, find your way towards those junk, collect those and finally recycle those.
And these robots will turn to junk as soon as they break down, possibly not doing enough cleaning job in its lifetime to offset its contribution in increasing the junk.
Basically making robots work to decrease entropy of the universe. Vision of the future. :-)