People worry that comic shops will go extinct one day, but I think there's always going to be hold outs no matter what. Why? Because of things like FCBD (Though I agree with Ken Eppstein of Nix Comics and it should just be Comic Book day) and things like Man of Steel day.
If you go to your participating comic book shop on Wednesday, June 12, then you'll receive a free special edition of Action Comics #1 and will also be able to purchase the first issue of Superman: Unchained as well. I know at this point basically everyone owns a copy of the new Action Comics, but consider this: Marvel gave away the first Ultimate Spider-Man for FCBD so many times that eventually the first prints of the FCBD edition actual have a value now. Yeah, a free issue is worth money.
That's not the only reason you should go as DC/WB is sending promotional posters and bags to shops and it will also be the first day to pick up some of the grotesque action figures they've created for the film. DC even has you covered if you're a digital fan too, but fuck that shit you can look it up on your own.