Yes, money is good. So are celebratory dinners. But one surprisingly underused weapon in most leaders’ motivational arsenal?

A simple note.

It doesn’t have to be long, maybe three sentences at most. But a short note that compliments someone on what a good job she did — as long as it is genuine — can have someone walking on clouds.

So why don’t we send more of them?

I think there are three reasons. For starters, it takes time. Second, we tend to be verbal in our praise — telling someone, “good job,” for instance — and we think that suffices. Also, some of us perversely note that when you praise a person effusively, that person often doesn’t repeat the performance the next time around.

But here’s the problem with these excuses. First, it takes no more time to write a three-sentence note praising someone’s work than it does to write an email scheduling a meeting for Tuesday. Second, you can’t save a conversation — there’s no returning to a conversation quite so clearly when you’re feeling down about things. A written note has staying power. Even if it comes via email.

And finally, much of what we do repeatedly involves skill and luck. Since luck is variable, these actions suffer from a regression toward the mean. And we only give praise for doing a great job, which, being a combination of skill and luck, will only continue as long as Lady Luck lingers. And she is random.

In other words, even if a note of praise is followed by a let-down in performance, that doesn’t mean it didn’t work. It probably motivates the person to keep trying, which will produce more good work in the long run.

I think this is a great resolution: Try to write at least one email per week that someone will want to print up and save. Who could you write a note to today?