THE INTERNET now offers more streaming movies and TV shows than free IQ tests. Of all the options out there—YouTube, Hulu, Joox, and so on—I pay fealty (and nine bucks a month) to Netflix. Their “Instantly Watchable” feature is intuitive, unlimited, and commercial-free, and it even integrates with my regular rentals.

A nice side effect to this set-up is the movies one discovers, and this seems especially true of documentaries. In fact, Netflix's "Instantly Watchable" catalog includes more documentaries than any other genre—twice as many as, for example, the "Action & Adventure" category. Now, Enron: The Smartest Guys in the Room may never attract as many viewers as Spider-Man 3, but it's nice to know that Netflix gives it a chance.

Viewers aren't the only ones who benefit from this arrangement. Documentarians often struggle with distribution: there's a whole world of quirky subjects and cheap camcorders, but how to get the finished product to the masses? Netflix provides a cheap, inclusive answer. Since they're often lo-fi to begin with, documentaries also suffer less on the smallest screen, and their shorter running times makes them perfect for online viewing.

One of the many Netflix-able documentaries worth a viewing is The Education of Shelby Knox. It place in Lubbock, Texas, a chain-store town full of big trucks and bigger cowboy hats. Unfortunately, Lubbock lives up to another rural stereotype: an excruciatingly high rate of teen pregnancies and STDs. Nevertheless, the local high school maintains its policy of abstinence-only sex education, even as nice, normal teenagers like Shelby Knox begin to question it.

As the film opens, during Shelby's sophomore year, she joins the Lubbock Youth Commission to campaign for comprehensive sex ed. Shelby surveys people in parking lots, organizes rallies and meetings, and gives interviews—lots of interviews. (She probably doesn't share Paris Hilton's morals, but may well share her publicist.)

Complicating Shelby's crusade is her personal life. She describes her family as "strongly conservative and Christian" and, early in the film, completes her own "True Love Waits" pledge. The rest of the film finds Shelby—and, just as much, her affable parents—sorting out the conflicts between personal beliefs and political realities.

Netflix might be commercial-free, but you should expect some bias in Shelby Knox. When its directors, Marion Lipschutz and Rose Rosenblatt, include shots of the Knox family's chintzy Christian decorations, the snark practically pulses through the screen. More seriously, Lipschutz and Rosenblatt never explore any real arguments against premarital sex. To be fair, the local frost-tipped pastor Edward "Sex Ed" Ainsworth isn't the best interlocutor; at one point, he compares sex ed to "teaching every kid how to use a gun." But when the directors do show Ainsworth's presentation, they only hit the hysterics—the corny jokes, the tearful pledges—and not the actual content. Plenty of secular examples (like this New York Times Magazine article) demonstrate that a pro-abstinence case can be made, and that interesting reporting can result from it.

Lipschutz and Rosenblatt's one-sided approach ultimately hamstrings their film. By Shelby's senior year, the students bring the sex ed issue before Lubbock's school board. The meeting actually kicks off with a prayer, and the abstinence advocates fall into a debate over the use and meaning of the word "condom" that matches anything Bill Clinton ever did with "is." In short, it's great theater, and it only intensifies when a cowardly school official tries to use Shelby's own "True Love Waits" pledge against her. Instead of expanding on this, though, Lipschutz and Rosenblatt abruptly switch to Shelby's decision to advocate for a straight-gay alliance. While this is an equally intriguing cause, the film sputters and then falls apart. It would have been better served by sticking with sex ed and exploring it more broadly (and more fairly).

What does this have to do with Netflix? For a documentary, Shelby Knox received a surprising amount of attention at its 2005 release—reviews in the New York Times and the Wall Street Journal, a broadcast on PBS's "POV" series, even a mention in a Dixie Chicks song. Since then, though, it's faded into pop-cultural oblivion. Good luck finding it at Best Buy or Blockbuster.

This is a path followed by most documentaries, and even most movies. But Shelby Knox is still worth watching, even when it falters as a documentary, because of its subjects. Whatever else they do or don't, Lipschutz and Rosenblatt tackle a thorny issue and a small-town locale, bringing needed attention to both. And Netflix's "Instantly Watchable" service continues to provide a home to fascinating but flawed stuff like Shelby Knox and its less-hyped brethren.

Of course, as online viewing becomes more popular, Netflix will acquire the rights to bigger and better content. Let's hope they continue to give us interesting, offbeat films like The Education of Shelby Knox. Call it comprehensive streaming.