Morgan Spurlock is back in top form with a witty, engaging documentary. The Greatest Movie Ever Sold explains how product placement works, by trying to make an all product placement movie. I’m still left with a few questions, but the film ultimately succeeds.

Spurlock lays out how we see products on coat hangers, gas pumps and urinals. Shows like “Chuck” and “90210” blatantly incorporate Subway and Dr. Pepper into their dialogue. His mission is to finance a whole movie on product integration and enjoy the success that blockbuster movies have with fast food tie-ins. He needs 1.5 million dollars.

Greatest Movie is less animation gimmicky. The humor comes more from Spurlock’s own personality. His ideas for commercials are hilarious. The commercial pitches from actual Hollywood campaigns aren’t as funny. Some classic visual bits include a reminder of the 6 1/2 year anniversary DVD of Supersize Me. Three actual advertisements for Pom Wonderful, JetBlue and Hyatt seamlessly incorporate into the movie.

In his meeting with Ban, Spurlock displays hilarious photos of himself using Ban in blatant ways. The medicine cabinet shot was my favorite. Spurlock even stumps the executives on a question about their own brand. He gets $50K from Ban. The local PA fast food gas stations Sheetz love Spurlock’s ideas for collector’s cups, but his real bonanza is Pom Wonderful pomegranate juice. They commit a million.

Even his rejections are funny. He cold calls companies like Volkswagon, Nintendo, Nike, Jolt Cola and more. He’s honest about his reputation and intentions. He’s not spoofing the products, but they know him for ridiculing McDonald’s. When he gets Minicooper, he does trash talk VW and the delivery is perfect. On a call with Mane & Tail, he can barely keep a straight face.

With the deals in place, Spurlock gets more analytical. Noam Chomsky, Ralph Nader and other experts analyze the risks of an artistic compromise and the lasting effects to Spurlock’s reputation. Hollywood directors like J.J. Abrams, Peter Berg, Brett Ratner and even Tarantino comment on product placement. People will slam Ratner for his complacence but he has a sense of humor.

A fascinating subject is Norm Marshall. His agency controls all the products in Hollywood. He’ll withhold your cars if you show Alka Seltzer in a negative light. That’s something I didn’t know happened. The example of Sao Paolo, where outdoor advertising was banned, provides a perspective on the cultural impact of advertising. Spurlock buys some banner ads at schools and in school buses so he does some good to help fund education.

I’m still left with the big question of: How does this actually work? I mean, I like Dr. Pepper. I’m not going to drink Coke no matter how many times Will Smith holds it up in a movie. Spurlock studies the science of the effectiveness of ads but that’s theory. I don’t see it, but maybe I just have strong will power. Greatest Movie Ever Sold still succeeds in both the experiment, and in entertaining.