We’re always looking for new ways to sell copies of my wife’s book, DC BABY. (Lowering the price works every time, but that has the added effect of, well, lowering the price.)

The book is available through a variety of vendors, including Amazon. The latest edition of the book has been available on Amazon since fall 2008. But even though the book has sold at a steady clip, no one posted any reviews until last week. As of today there are 11 reviews, nearly all with a 5-star rating. How did we do it? It’s simple: We asked. We also offered a free e-book in exchange for an Amazon review. Less than half of the reviewers requested the e-book; the rest just did it because they felt like it.

The results? In just one week, sales for the month have nearly doubled, as demonstrated in this chart: