When they use social media, authors have as many personae to choose from as they do in their other writings. Some strike poses that effectively increase the distance between them and their readers, foiling voyeurs. Gary Shteyngart (4,187 followers), whose first tweet was posted on Dec. 1, is charming yet enigmatic (“grandma always said to me, ‘boytchik, do not start a meth lab.’ but i guess i had to learn the hard way”), and often writes in the voice of his dog (“woof!”). When I asked if he enjoys interacting with readers on Twitter, Shteyngart responded: “There are so many clever people out there. I love each one of them. Many times I laugh with them.” Humor is common and welcome in authorial tweets. One of Twitter’s funniest is Mat Johnson (39,712 followers), who told me he consciously becomes “Mat Johnson, author and humorist,” on Twitter. (“Teenagers hanging out at a playground, laughing to each other at how ironic they’re being. I want that made illegal.”)

Johnson does more than quip; he engages with others: “The people I follow, they are my dream party guests, interesting strangers whose wit keeps me coming back.” Jennifer Gilmore (3,463 followers) finds hearing from readers helps her understand the influence her novels have on them: “On Twitter, I have a sense that people — those you know and those you don’t — read your work in a way I have not always felt in the world.” For the poet D. A. Powell (2,443 followers), interacting with readers on Twitter makes him feel “like I’m living in the future. I imagine that’s the feeling all writers want to have.”

Holdouts like Eugenides often cite the need for solitary reflection. Wells Tower has said that “the Web . . . is . . . toxic to the kind of concentration fiction writing requires. It’s difficult to write good sentences and simultaneously buy shoes.” But of the idea that writers require absolute solitude, Powell wryly notes, “That certainly worked for John Bunyan when he was in prison.” Of the “I want to be alone!” type, Jennifer Weiner (34,682 followers) says: “I sometimes read about authors who say they require a perfectly silent room maintained at precisely 68 degrees, with trash bags taped over the windows and a white-noise machine in the corner to write, and I think, ‘Who are these people, and do any of them have kids?’ ” Johnson concedes writers need uninterrupted time, “but only about four hours of it. We are awake another 18 hours. We have to do something with our thumbs, right?” As Margaret Atwood told me: “Every writer is two people (at least). There’s the one that does the writing, and the one that has an egg for breakfast. I’m the other one.”

Weiner notes that the publication process has always been collaborative. With social media, she can bring readers into it, so “they have a say in an author’s career, whether it’s giving feedback on a cover or a title, or voting on book-tour cities.” Darin Strauss (1,979 followers) enjoys what Twitter offers after the promotion process is over: “It’s nice to hear dispatches from the front. When you publish a book, you can forget — after the reviews stop coming and stores clear space on the front table for newer stuff — that people are still . . . reading the thing.” Johnson is grateful to social media, since he doesn’t benefit from massive publicity. “I’ve never had a single ad for any of my novels, had a movie made or been given a big budget push by a publisher,” he said. “Usually, they just throw my book out to reviewers and hope it floats. Twitter lets me hijack the promotion plane, sidestep the literary establishment and connect directly to my current and potential audience. . . . It’s a meritocracy; if you’re interesting, you get followed.”

Of course, not all readers want to hear about Atwood’s breakfast. On why she doesn’t follow authors, one reader tweeted: “Following an author is kind of like looking behind the curtain, isn’t it? Why ruin the illusion?” A few big-name authors post to Twitter but do not intermingle, keeping the curtain drawn. They post about coming releases and tour dates, but are not social. Their personae, more corporate than individual, are vulnerable to lampooning on false and parody accounts, like ­@EmperorFranzen, that commandeer an author’s voice.