Once, before I was published, I gave some thought to one of the most common — and potentially intrusive — questions that children’s authors get asked by members of their target audience.

In the past few weeks, I’ve frequently received a variation on that question — from adults.

“How are the book sales?” they ask.

This question strikes me as genuinely curious, rather than nosy: Amazon.com sales rankings are just one of the many real-time popularity measurements we’ve gotten used to seeing for contemporary cultural artifacts, and my questioners (correctly) assume that I’ve got a better idea than they do of where The Day-Glo Brothers currently ranks.

It’s also a very sensitive, fickle metric — a book’s ranking can jump or fall frequently within a single day (or so I’ve heard) — which makes it hard to get a clear view of the trend, at least if you have anything else going on in your life. What’s more, sales through one giant online retailer in no way reflect sales of the book through the local, independent retailers to which I prefer to steer would-be buyers.

So, how am I going to answer that question about book sales, assuming that I don’t just choose to deflect it entirely? I think I’ve found my answer in FirstSearch. A week ago, that service told me that 56 US libraries had copies of The Day-Glo Brothers. Today it says the count has climbed to 83.

Is 83 a lot, considering the official publication date was July 1? I have no idea. I do know how that figure compares to the other picture book biographies that I mentioned during my presentation at BookPeople a couple of weeks ago:

501 for George Crum and the Saratoga Chip
1,562 for Boys of Steel: The Creators of Superman
2,731 for The Dinosaurs of Waterhouse Hawkins

I also know how to do basic math, which tells me that this week’s library count is 48% higher than last week’s. And in this economy, a measurement in my favor that’s heading in that direction is one I sure don’t mind telling folks about.