Free Comic Book Day (FCBD) is an annual promotion within the national comic book industry to help bring new readers into independent comic book stores like Comic Zone. Free Comic Book Day is scheduled on the first Saturday of May, where it started in 2002, and it is coordinated by the industry's single large distributor Diamond Comic Distributors.
In recent years, it has often been tied to the release of a major theatrical film adaptation of a well-known superhero property, in order to take advantage of the film's heavy promotion and related press about the comic book medium. There was no theatrical tie-in in 2010, although Iron Man 2 was released the following Friday, leaving some people to speculate whether the movie industry incorrectly scheduled its release for the first Friday in May, thinking FCBD would be the next day, when in fact, FCBD was on May 1st.
On Free Comic Book Day, participating comic book store retailers decide how to give away their specially printed copies of free comic books, and some offer cheaper back issues and other items to anyone who visits their establishments. Retailers do not receive the issues for free; they pay 12-50 cents per copy for the comics they will give away for free but as Psycho Andy would tell you, it's business suicide to not participate, and the increased traffic the day provides makes up for the event's expense.