Needless to say, I was pleasantly surprised to realize that I had done this without consciously deciding to do so.
An author brand is something that marks an author's books as being unique to that particular author. You can look at a book's cover and immediately recognize that the book was written by a certain author or belongs in a certain series. My author brand, unique to my Black Horse Campground series, is the black horse logo that appears on all my book covers and the tag line "A Black Horse Campground mystery". If you write a series, this is a great marketing tool to help fix your series in the minds of readers and also to set the series apart from other books or series you might write. A great example of this is OTP's own, Marilyn Meredith, who writes two different series. Her Rocky Bluff P.D. series, published by Oak Tree, features a police badge on every cover and distinguishes it from her other series.
Another way to brand your books is to have a recurring title tag. Radine Trees Nehring writes a series in which every title contains the words "to die for". Dac Crossley's "Texas Ranger" series includes--you guessed it--the words "Texas Ranger" in each title. The tag line can be either part of the title or a subtitle to identify the series, such as my titles (example: "End of the Road: A Black Horse Campground Mystery")
There are other ways to brand your books whether they go in a series or not. Using the same font for every title, the same color scheme, or the same layout for the cover can also identify your books as belonging to a series or to the same author. Mary Montague Sikes does this with her landmark lodgings series. Holli Castillo combines a number of these elements in her covers--recurring font, black and white scheme, and the word "justice" combined with Cajun recipe names.
With so many books in the market and the possibility of so many similar titles (and author names!), developing a unique author brand to distinguish your books from others is a good idea to keep in mind, whether you write a series or not. When you find your fans and reading audience, make it easy for them to find you!