I've mentioned before that I would pay to use this product.
If you had the same tool that worked with a blog search API not only would I pay for it, but you could sell it to SEOs all day long. Just need to find a decent blog search API; I haven't had much luck.
If someone here were to market this product, do you have any suggestions as to how they could reach other customers as well, enough to make it a sustainable business?
It is a good idea for a service, if possible please consider something like https://www.mobileworks.com/ as vincvinc mentioned below that tries to be socially responsible for crowd sourcing instead of mturk.
At the kind of scale I would use it at I would just hire personal assistants.
That said, I've actually used mechanical turk to earn money in some of my low points (was living in my car working on a startup, out of cash, crazy/long story). I didn't make US minimum wage, but if I were living in Bangladesh, for example, it would have been OK money.
It could be any range of blogs; it's one of the most effective and least-used means of marketing.
Say I'm a bowtie company that sells to designers; I could look for all the fashion blogs by searching "bowtie" or "necktie," etc. Just generic blog outreach, whether it's little blogs or mommy blogs, would be very useful. Not only do you get some traffic from those blogs, but you get the link juice of some really good links.
If you had the same tool that worked with a blog search API not only would I pay for it, but you could sell it to SEOs all day long. Just need to find a decent blog search API; I haven't had much luck.