Why ask with a question?

Two decades ago I ran across this article. I refer to it every time I seek to convince a volunteer to ask with a question “Can we count on you to vote for Barack Obama?” instead of asking with a statement: “Please vote for Barack Obama.” I told people that a restaurant owner had found that switching to asking with a question cut their no show rate in half. I have thought many times about trying to find this article. I never did, in part because I was afraid that I was exaggerating the effect. Did they really say that it cut their no show rate in half? No it did not. It was better than that. It said that it cut their no show rate by two-thirds. The interesting paragraph is buried, so here it is:

He instructed his receptionists to stop saying, ”Please call us if you change your plans,” and start saying, ”Will you call us if you change your plans?” His no-show rate dropped from 30 percent to 10 percent. In other words, by asking a question and eliciting a response, he created a sense of obligation.

PS I like the idea of asking voters for their credit card information and telling them that they can avoid the $300 no-show charge simply by voting. [JK]