This is no different than the scaling limits of many online media companies, in fact. 83% of the US population is in an urban center. 81% of the US population has access to broadband internet (and not all of them take advantage of that access). Netflix's addressable US market for streaming is smaller than TaskRabbit's for tasks.
If dealing with logistics issues at scale would have been easy, your grocery store would have been able to deliver to your home. Do they ? No -- because its not cost efficient due to the logistics involved.
The purpose of the comparison to Netflix was to emphasize that the addressable market for your product or service need not be "every household in the nation" to be considered "at scale". It's OK for TaskRabbit to never offer all its services in every suburb -- because it's logistically difficult or impossible -- they still have the potential to be a large, profitable company without doing so. I never made a comparison between how easy or difficult it would be to grow.
But I imagine they either don't scale to the suburbs at all, or if they do, it will be more expensive to hire people in the suburbs, reflecting the higher cost of providing the services.
It's for the same reason I doubt they will ever came to rural areas. It's okay though, not all services have to be everywhere.
http://www.theatlanticcities.com/neighborhoods/2012/03/us-ur...
'According to the Census Bureau, a place is "urban" if it's a big, modest or even very small collection of people living near each other. That includes Houston, with its 4.9 million people, and Bellevue, Iowa, with its 2,543'
That counts all 4.9 million people in the Houston Metro as being "urban", which is a joke. Maybe a few hundred thousand tops live in what you might characterize as a real city environment-the vast vast majority of is suburbs
>"Maybe a few hundred thousand tops live in what you might characterize as a real city"
Manhattan alone contains 1.6 million people; your few hundred thousand tops estimate for the U.S. urban population is very short.