My wife and I agree that we should not reward our children for things we consider a requirement of being a part of our family: education, chores, charity, manners, etc.
That being said, I think there's no reason why kids can't have more fun while they're learning. And if it helps them study/practice longer, what's the harm?
I agree that your title is more exacting. :)
That being said, he says clearly that this is about learning math facts. The are the one rote part left in the early math curriculum. It's going to be painful for most kids. I know this from very recent experience. Anything you can do to help I think is advantageous.
He should not have titled his post as he did. It should have been titled "How to get any 3rd grader to learn their math facts more efficiently". I think that's what he meant to say anyway.