The U-T frequently invites guest speakers into the newsroom to discuss writing and journalism, and this week we hosted literary agent Sandra Dijkstra. Her Del Mar-based agency is marking 40 years in business this year, and she’s among the most prominent agents on the West Coast, representing authors such as Amy Tan.

Dijkstra gave a brief overview of the changing book industry: 41 percent of all books are sold via Amazon with Barnes & Noble at 23 percent, which was higher than I expected given all the bad news we’ve been hearing about the chain. (Independent bookstores sell only 6 percent.) Also surprising: Print book sales are increasing, e-book sales are down.

One of her main reasons for talking with a bunch of journalists was to tell us that nonfiction books are selling better than fiction, especially current events/politics. Journalists have built-in credentials and have an innate sense of what makes a good story, she said. Agents spent lots of time scouring newspapers and magazines in search of stories that could be turned into a book. The trick is find something that can be elevated beyond regional interest.

Dijkstra says the role of agents is to determine if an idea can sell, help refine it, and decide if the author is the right person to write it. Staffers were invited to send her a pitch for a book and have her evaluate it. It was instructive to hear a top literary agent deftly take apart the ideas and suggest improvements. Listening to her was a timely refresher course for me because I’m deep in the process of developing my next book. As I do so, I will keep her advice for authors at the forefront of my mind: “Come up with a good idea that suits you that you can present persuasively.”