I think there's a category of these kinds of things where you apply AI to do something humans could do, but could not be bothered to do. Or could not profitably do. At least no human would categorize all these reviews just for lols.
Another recent example from HN would be that site which just lists hotel rooms that have a desk and a chair. It would be an incredibly dull task for a human to look at a million hotel room pictures and just select if they have a desk or not.
What else somewhat useful/fun could we do applying perhaps a little worse than human attention at something, but a lot of it?