You’ve seen the movie, now read the book - for free!

The movie is Spider-Man 2, which opened Wednesday and pulled in a record-breaking $40.5 million, meaning plenty of you were there. And if that’s not enough Spidey to satisfy you, simply truck on over to your friendly neighborhood comic-book store today and take advantage of the third annual Free Comic Book Day. If the store is one of thousands participating in the nationwide promotion, you can walk away with a comic book - Spider-Man is one of about 30 titles being offered - without plunking down a cent.

"The primary reason we are doing this is to remind people of the power and the intensity of comic books," says Barry Lyga, marketing and communications manager for Timonium-based Diamond Comic Distributors. "People love the Spider-Man movie, The X-Men, Smallville on TV. This is a way of reminding them that, hey, these characters began in comic books."

The idea originated in California when comic-store owner Joe Field floated the idea past the folks at Diamond. "We thought it sounded good, and everybody we talked to thought it was a great idea," says Lyga. Not coincidentally, that first free day coincided with the release of the first Spider-Man film, which set the single-day box-office record its sequel just broke.

That first year, only a handful of comic-book publishers participated, providing the specially designated books to be distributed to anyone who walked through the door. For 2003, the number of publishers grew to about 30, about the same number as this year.

"We love Free Comic Book Day," says Gui Karyo, president of publishing for Marvel Comics, keeper of the Spider-Man franchise. "Anything that encourages kids to read, or anyone, really, to read comic books, is phenomenal."

The numbers suggest Free Comic Book Day has been a hit. About 2 million free books have been distributed each year, Lyga says. He notes that stores participating in the first two promotions reported that, on average, 45 percent of the people who showed up were either new or lapsed customers and that 78 percent of them were still coming back a year later.

Locally, several stores are planning in-house promotions for today. Owner Marc Nathan of Reisterstown’s Cards, Comics and Collectibles is bringing a handful of comic-book artists and writers to his store. (One will be Maryland’s own Frank Cho, responsible for the Liberty Meadows comic strip and book, who will soon be the artist on one of Marvel’s myriad Spider-Man titles.) And Sheldon Pearlman, owner of Comics Kingdom in Hampden, is holding a storewide sale to run the entire weekend.

"People get exposed to a lot of books that they never would have been exposed to before," says Pearlman, noting that, in previous years, the weekend has been filled with regular customers anxious to take advantage of a bargain.

For Nathan, it’s all about getting people in the door, comics fans or not.

"In the worst possible scenario, you’re rewarding all your customers with free comics," he says. "The best possible scenario is that I’ve reached people that possibly saw the movie, and they want to see more or read more or know more. Giving them free stuff is a great way to start."

For a list of stores participating in Free Comic Book Day, check the Web site at www.freecomicbookday.com.