For the last decade, viral videos have pushed the envelope of what constitutes an ad. Remember the infamous sock puppet ad for the now-defunct that ran during the SuperBowl? That was long before YouTube, and just one early example of strangely compelling marketing exploits.

Another trend, one that has been around for at least a few years, is to make an ad look like pure entertainment. The recent VW ad where a kid is acting like Darth Vadar is one good example, and many of the recent T-Mobile ads show a magenta-clad biker racing around without ever using a phone. The casual viewer might not even realize which company is involved until the logo appears.

Ad? What ad?

Now, there's a new trend: digital shorts that run for as long as three minutes and appear to have no discernible advertising ploy. There might be well-known actors who perform crazy stunts, and the product makes only a brief cameo. One recent example: During the Emmys, a digital short with Parker Posey explained, in sardonic terms, how to do an Emmy acceptance speech.

The bit is hilarious. Some of the actors who appear are in real TV shows. Posey does her usual routine where she is overly earnest and self-aware at the same time. Then, we finally see her walk by an Audi S7 and interact with some of the speech recognition systems. Even then, it's hard to know for sure that this purely an ad, especially since she pokes fun at the feature.

Andrew Lipman, a general manager at Audi, told me that, for any small business, the goal is often to create an event--something that people start talking about and sharing with each other. There is no strict formula, he says, for how much entertainment you add and how much of a product you show. The Audi short, produced by PMK*BNC and Paulilu Productions for Audi, shows the car for only about 10-20 seconds of the digital short.

"It's a delicate balance with digital shorts," says Lipman. "There needs to be enough branding so that we feel like customers are taking away that Audi was involved. At the same time, people are extremely savvy. They're not interested in being tricked into watching commercials."

Focus on Fun

Lipman says any small business can create a digital short, and his advice is that you don't necessarily need a big name star involved. The trick, he says, is to create a short that is purely fun, entertaining, and shareable, but also has a clear product segment.

One of the best examples of this is the ad for

The video is purely entertaining from start to finish, and doesn't switch to a serious sales pitch to buy the product. In many ways, the digital short plays out like a skit for Saturday Night Live, and you barely notice any branding. Many of the commenters on YouTube were surprised to find out it even was an ad.

Yet, the name sticks--you remember the brand and the comedic bits at the same time. Lipman says that is the goal: Raise awareness for your brand, get people talking, and add some entertainment value.