What's up with the title? Quentin has that covered in the opening credits. The first thing we see on the screen is a definition of pulp. "Pulp" could mean "a soft, moist, shapeless mass of matter," which sounds pretty gross so we just like to think of fruit pulp, like, the stuff that some people don't want in their orange juice (because we all know the best kind of juice is the least natural; everyone loves Capri Suns).

Okay, so that's one kind of pulp, but the movie also gives us a second definition: "a magazine or book containing lurid subject matter and being characteristically printed on rough, unfinished paper."

We're starting to get an idea of what the movie's gonna be like.

Pulp magazines were sort of the Marvel movies of the mid-20th century. They weren't very artistic or original but they were a big part of pop culture. The subject matter was over-the-top sultry and often involved crime/detective type narratives because what's not to like about crime and sultriness? Also it's probably not too hard to write serial installments of it.

With the introduction of paperback mass-market books, the magazines grew up to be pulp genre books with racy covers and titles like Leave Her to Hell and Scandal at a Nudist Colony. Louis Menand writes: 

"Scantily clothed women and sexually suggestive scenes, whether the author was Mary Shelley or John D. MacDonald, became almost a requirement of the format. If the book was a hardboiled-detective novel or a mystery, the requirement was a woman wearing a peignoir and holding a gun." (Source)

Menand points out that this even put pressure on publishers of paperback high-minded literary fiction. The cover of the 1950 paperback reprint of George Orwell's 1984—about as serious a book as you can get—said "Forbidden Love. . . Fear. . . Betrayal!" and showed images of the main characters with ripped biceps and plunging necklines. Pulp fiction was the industry disrupter of the time, redefining what could and couldn't be put in print. Menand again: 

"What you could publish in the United States and Britain in 1965 was radically different from what you could publish in 1945, and pulp paperbacks were part of the reason. In the process, the pulps lost their clout in the book business. But they died so that Philip Roth and Erica Jong might live." (Source)

The same sort of stuff that was used to sell pulp magazines and novels is everywhere in the film. Crime? Check. Sexiness? There's a reason Mia Wallace is on the movie poster. Check. Violence and shock value? Check. Pop culture references? This is Tarantino we're talking about, so that's one big—check. It's also is a sort of serialized format.

Quentin knew his pulp fiction.