According to a Pew poll, six million adults—almost a third of the number who own personal audio players—have downloaded podcasts. A lot of people are listening. A podcast is a self-published online radio show available to download from the Internet. Although the concept was only born four years ago, Apple’s iTunes directory currently lists more than fifteen thousand podcasts available for download and receives more than a thousand podcast submissions each week.

One of the reasons for the podcast’s quick rise to popularity is how easily one can be created. Desktop programs like Apple‘s iLife ($79) include everything you need to record your own. You can get a detailed how-to at Podcasting News or listen to a podcast about how to podcast at Apple’s iLife tutorials. Of course, unless you have your own recording studio, using do-it-yourself programs will make your podcast sound like you did it yourself. If you are trying to sound professional and want your podcast to reflect that professionalism, then you should look into a company that will help you record and edit.

Here are the essentials to make sure your podcast rocks the trend and ensnares faithful listeners everywhere.

Hook ’Em: No one is going to download “Bob’s Random Thoughts Podcast.” Why should I care what Bob thinks? But if Bob had a clearly defined thought, I might be persuaded to download. That clear thought is the hook, the promise that gets a listener interested in your message. Your hook should involve a catchy title that immediately tells your audience why they’d want to listen, and content that’s useful and interesting enough to get your downloaders to click that “Subscribe” button on their iTunes. The Three N’s help you craft a hook: Need, Novelty, and Newsworthiness.

• Need: Like I said before, people need a reason to download your podcast. Regardless of what your targets are looking for, there is a reason they want the information. Whether they’re curious about what Tim Gunn thinks about the new episode of Project Runway or looking for sound stock tips, your audience is drawn in by information relevant to their lives. If you clearly define what you are podcasting about and show their need for it, people will be more apt to download it.
• Novelty: We all gravitate to the original, the new, and the unusual. Spread your message in a different and unique manner. If you are podcasting on a popular subject, make it your own. Your podcast should reflect who you are and how you want your message to be heard.
• Newsworthiness: This does not mean your podcast should focus on the hard-hitting, late-breaking news, but it does mean your podcast should be timely. Choose a hot topic—if “Bob’s Random Thoughts Podcast” became “Bob’s Predictions on the Final Harry Potter Book” or “Bob’s Snakes on a Plane Exposé” people would download it, because both subjects revolve around hot, newsworthy topics.

Where It’s At: No matter how good your hook is, as with any type of promotion, visibility in the marketplace is critical to delivering your message to the most people. Your podcast should be listed on every podcast directory out there. The most important is iTunes; they have top-of-mind awareness, and if your podcast offers creative material and a fresh outlook, they might even feature it on their podcast homepage. Besides iTunes, there are several other directories where you should list your podcast: Odeo, podcast.com, Juice, and iPodder. To build a successful following, try to release one show every week. Keep your audience coming back for your latest installment.

Work It: If you hook an audience and have high market visibility, then you can work the advertisers. Just like you have space for rent on your website, you have advertising space on your podcast. With advertisers and sponsors you can increase your visibility and expose your podcast to more listeners. For example, if you were podcasting about jogging as a sport and a pastime and developed a strong following, why not approach Nike or Gatorade and pitch a cross-promotional deal? If you can present them a built-in audience, you’re offering a great place for them to promote their products.

TIP: Go to iTunes and browse their podcast directory for inspiration; see what everyone else is talking about. For examples of the podcast done right, check out the podcasts “Ad Age Audio Reports,” “Authors on Tour Live,” and “The New York Times Headlines.”