Strangely, here in the Detroit area, none of the stores that stock a lot of roleplaying games participated, but
RIW Hobbies, which barely stocks roleplaying games
did participate. So I finally went to RIW Hobbies, a store I'd never had a good reason to visit before now.
They underwhelmed me. Apparently they didn't see Free RPG day as any sort of opportunity to encourage new customers. I bought a bottle of Zap-A-Gap and Gale Force Nine "Wall of Fire," picked up the free Dungeon Crawl Classic, and that was it. They didn't even have a sign in the window. (They were actually hanging signs up for a Magic tournament while I was there!) The 2 employees spent most of their time discussing some dude's tournament rankings.
Contrast them with my friendly local comic books store during Free Comic Book Day: They had local comic creators set up with tables, they were giving extra comics for joining the store mailing list, and even got the record store upstairs to give away stuff. That's a store that gets new customers from Free Comic Day. (In fact, they got me because of Free Comic Book Day last year.) I had to park a mall down the block because the comic book store's lot was full!
So, "hooray!" for Free RPG Day, "meh" for my stereotypically-mediocre FLGS.