It's also worth noting that this is famous enough that Amazon has offered a service called Mechanical Turk since 2005.
The implementation and service are both fine in theory, but you do need to be clear that what's being paid for is humans pretending to be computers.
Maybe folks just like symmetry.
If your comments are going to gum up the thread with a segment that they don't think will have any effect, what's a few more to match?