Wouldn't it be great if your marketing videos spread like the plague? It's not easy to design a “super bug,” but here are suggestions to get started.

1. It's infectious. Want to go viral with your marketing? Well, you'd better have a video that's infectious. A good viral video makes viewers feel something. It starts a fever. You aren't playing politically correct or targeting the most people you can with viral marketing. You're shooting for emotions. Get under people's skin, make them laugh, upset them, do anything that makes them feel. Make it compelling enough that they feel the need to pass it on. Viruses don't play nice, they play to win.

2. Not the common cold. Prospects aren't looking for common advertisements in the videos they share among their friends and co-workers. So don't advertise. (Get them later, after they're hooked and aware of you.) Tell them a hilarious story. Surprise or shock them. Interrupt and offer. Get the viewer's attention and let them know where they can get more information.

3.Time to gestate. Unlike blogs, viral videos don't have to be updated all that often to be effective. If they're really good, they just need to be there. Most actually gestate on the Web for awhile before someone picks them up and passes them along. But when it catches on, it spreads like a contagion.

4. Restricted access — not! To enable the viral video's communicability, don't restrict access at all. Let anyone post it anywhere. YouTube is great about this. Anyone can upload and share a video, and anyone can post your video on his or her blog, send it via email, or link to it on their Facebook or Twitter account. If you're doing your job right, there will be knockoffs before long. This isn't plagiarism or intellectual property theft. This is success.

5. Numerous strains. After you have a successful viral video, don't stop. And don't reinvent the wheel. Once you have viewers hooked, develop your subtle messaging in successive related videos that build on what you've created. For instance, develop a sequel, or make a bloopers reel from the original, or a video about why you made your video, or a contest for spoofs of it.

Once you win attention on the Web, fight to keep it. Fight hard. —Rich Harshaw, author of Monopolize Your Marketplace, is a marketing expert; www.contractor-marketing.com.