You just walk in and pick up your free comics. It's a great way to get a couple of free reads. Of course the plan (like any addictive substance) is that you'll get hooked and keep coming back for more.
I put a picture of one of the free comics on the side here in case, for instance, you happened to be looking at BHR one day and your son (who is too young to watch Spider-Man) happened to see pictures of Jesus and Spider-Man together and tried to convince you that meant he should be allowed to watch it. Now you can go get this comic FOR FREE and then hand it over.
NOTE TO PARENTS: If you have young kids, I'd suggest you read the comics before giving them to your kids. I personally always liked it when my dad read my comics. Now if I find a good one I let him read it when I'm done.
ANOTHER NOTE: If you're in the San Francisco Bay Area be sure to head over to Flying Colors Comics (my former workplace) to snag your free comics, and be sure to say hello to all my buddies there.