Virtual book tours feature authors promoting books by making guest appearances during a set time frame on blogs, podcasts, radio shows, social networks, or other venues. These tours are sometimes called book blog tours or virtual author tours or abbreviated as VBT. The author goes from blog to blog sharing information about their books.
The locations where the author is making appearances are called tour stops, and the blog owners or interviewers are called tour hosts.
Tours are often done as part of the launch of a new book, but they can be successful any time after the book is published. They are just as effective for fiction and nonfiction books—only the venues and the type of content will vary.