After a writing career of 40-plus years that has included 20 novels and stints as a newspaper reporter and Associated Press news desk editor, I've tried just about every trick in the game to increase my book sales. But I'm still learning new ones.

About four years ago I thought the Internet was the way to go. So I hired a professional to design a Web site for me—not terribly expensive but reasonably effective, I think. I hired another pro to take on the novel I'd just published, Dance with the Dragon. She flooded the Web with interesting articles about me and my novels, especially Dance, and generated a list of 500 important people around the country, especially in regions where my books seemed to do well. We sent ARCs with a short, nifty letter to each of them. I personally stuffed the envelopes and hand-stamped each one. That exercise cost me around $5,000 plus my time, and it increased my sales by about 20%. It was a lot of work, but it seemed to be reasonably effective.

For my next novel, The Expediter, in 2009, I did nothing on my own to promote the book. My publisher set up some local bookstore signings and a radio satellite tour. The book did well, its sales edging up just a tad from Dance.

In the year it took me to write my latest novel, The Cabal, which Forge published this past July, I took more time to figure out what it was that helped books sell. And I came up with two notions: first, not a new one, was that hand-selling works; second, that what makes it work is some sort of a rapport between the person doing the hand-selling (i.e., a bookseller) and the author. My brother-in-law, a former car salesman, once told me, "People don't buy cars from factories or dealerships. They buy cars from salesmen."

With that in mind, I put together a 16-day mini-tour, by car, starting from my home in Sarasota, Fla., and heading north through the state and on to Alabama, Georgia, North and South Carolina, back to Georgia and finally Florida, and home. I visited 33 bookstores in 16 cities.

The tour did include formal signings arranged by my publisher, but my real purpose was to meet booksellers and sign stock. I stopped into many stores that I just happened to find on the GPS in each city I visited. I was hoping to connect with the folks who actually recommend books to customers—and I know that there are still customers out there who will listen. At each store, I talked to floor managers and sales clerks. Of all the stores I visited, not one person was indifferent to having an author stop in. In fact, they were excited to have an author in person in their store. I left my cards and asked that if the store ran out of signed stock, they'd give me a call or e-mail me, and I would send them signed bookplates from my publisher. By the time I got home, I had three e-mails asking for them, one from a store where I had signed 50 copies of the book. A few days later, I got a telephone call from a Books-A-Million manager who asked if I could send book plates. "Sure," I said. "Five or 10?"

"More like 15, if you wouldn't mind."

I sent 20.

I was so pleased with the results of my mini-tour that I'm planning another one for my next novel, Abyss, which comes out next summer—this time 50 bookstores in 25 cities in 21 days. Because on my tour for The Cabal, I met a lot of people who were really enthusiastic about selling books. They were energetic, knowledgeable, smiling, excited people. Managers and cashiers alike thanked me, in some cases profusely, for taking the time to come see them and chat. My publisher graciously agreed to pick up a part of the roughly $4,000 travel tab. Best of all, my book sales showed another significant increase.

And I didn't have to stuff 500 padded envelopes.

David Hagberg is a former Air Force cryptographer and has published more than 20 novels of suspense, including the New York Times bestselling thriller The Expediter, as well as Joshua's Hammer, Soldier of God, and Abyss, due out June 2011 from Forge. He lives in Sarasota, Fla.