That's marketing speak.
How about: "Let's say you want to build a website that shows the different rates for parking garages around San Francisco, but you don't have the pricing data. Human.io can help you get hoards of strangers to run around the city, snapping pictures of pricing signs at garages, and uploading the pictures to you. Viola, now you have the data."
Is that vaguely what human.io can do?
You could do all sorts of things. How do I wrap it up into one sentence without marketing speak?
Edit to add: "a Mechanical Turk for tasks not easily done at a computer" isn't a bad description either.
...ask users to vote on them using human.io
humans = init({ count:100, gender:male });
task_navigate = task({ type:navigate, uri:{latitude:123, longitude:456} });
task_photograph = task({ type:photograph });
for (human in humans) {
human->task(task_navigate);
human->task(task_photograph);
}