Just like the famous shampoo commercial, there are numerous instances where consumers want to tell a friend, who then tells a friend, who tells another friend, and so on. To create something that will start such a viral chain reaction requires—you guessed it—quality content.

What “must share” content can you develop? While there is no sure-fire answer, here are some ideas to help you get rolling.

Inside Information: People like to feel that they have inside information, tips or news, or that they have discovered unique that their circle of friends, family or business associates have not yet seen.

Industry Information: Readers will always forward items that might be helpful to their professional colleagues. MarketingSherpa, for example, has determined that its audience of marketing executives to share case studies, results data and articles to stay on top of the latest industry news.

Ecards: Ecards have been an extremely successful means of viral marketing. Blue Mountain Arts, featuring a variety of electronic cards that are sent to friends and family for birthdays and other occasions, has enjoyed phenomenal success. You can produce your own email cards without great expense.

Inside Jokes: Jokes also work very well. But not just any jokes. Too many people are tired of the well-traveled routine jokes that land in their inbox from their aunt in Pittsburgh. You can, however, tailor your humor to fit your readers. Create tasteful, inoffensive jokes that appeal specifically to your audience. If you sell educational products, for example, an e-mail with jokes specifically written to appeal to teachers is ideal. Not only will teachers appreciate it, but they will likely forward these jokes to other teachers, who will appreciate the inside humor. This will quickly result in an extensive list of quality leads.

Games:Particularly when marketing to a younger crowd, games are a terrific and relatively inexpensive way to capture attention and build awareness. There are plenty of companies that develop downloadable games that you can post on your Web site.

Group Ideas:If your audience is likely to form a club around its favorite activity you can use it as an opportunity for one person to forward your e-mails to other club members. For example, a golf outfitter could offer to send discounts to the other three members of a golfer’s favorite foursome. An investment newsletter could invite investment club members to sign up their club for investment tips.

Things That Are Worth Their While:People will gladly pass along your information if there’s something in it for them. You can offer a simple incentive program for forwarding an e-mail to ten people, such as a coupon, a fun download, reward points, or something else of value to your audience. One of your advertisers or partners might be happy to provide you with a discount to offer to your subscribers if it drives business its way. One caution: As with any incentive, you risk that your prize is more of a draw than membership to your newsletter. Some participants will only stay on your list long enough to reap the reward and then unsubscribe or ignore future mailings. Rewards will never generate the same committed audience as quality content.

Off-beat Stories: If you intentionally conclude an otherwise business-oriented newsletter with a silly story, you increase the likelihood of having the newsletter, or that specific story, forwarded. The fun story prompts the forwarding of the entire content set, and your marketing messages go along for the ride. You can even build an entire newsletter around such stories. A case in point is Strange but True, a newsletter for human-resources professionals from our client BLR. The newsletter features unusual and entertaining stories that deal with various workplace scenarios, such as a recent story which documented the odd but actual happenings between toll collectors and drivers. Strange but True actually began as a final story in another of BLR’s newsletters, but it became so popular that it demanded its own venue.

Other Popular Favorites:Surveys, contests, cartoons, trivia and polls are all frequently forwarded. A case in point is a Web site called YouThink.com, which offers free blogs and journals. This site has built an ever-growing list of dedicated users, many of whom were first attracted by the fun and entertaining quizzes and trivia games circulated via e-mail.

Matt Blumberg and Michael Mayor are the driving forces behind Return Path, an e-mail performance company. Collaborating with them on this project are their colleagues, e-mail strategists Stephanie A. Miller and Tami Monahan Forman. This article was excerpted from their new book, “Sign Me Up! A Marketer’s Guide to Creating E-mail Newsletters That Build Relationships and Boost Sales (iUniverse Inc., 2005) © 2005 Return Path, Inc. All rights reserved.

Just like the famous shampoo commercial, there are numerous instances where consumers want to tell a friend, who then tells a friend, who tells another friend, and so on. To create something that will start such a viral chain reaction requires—you guessed it—quality content.

What “must share” content can you develop? While there is no sure-fire answer, here are some ideas to help you get rolling.

Inside Information: People like to feel that they have inside information, tips or news, or that they have discovered unique that their circle of friends, family or business associates have not yet seen.

Industry Information: Readers will always forward items that might be helpful to their professional colleagues. MarketingSherpa, for example, has determined that its audience of marketing executives to share case studies, results data and articles to stay on top of the latest industry news.

Ecards: Ecards have been an extremely successful means of viral marketing. Blue Mountain Arts, featuring a variety of electronic cards that are sent to friends and family for birthdays and other occasions, has enjoyed phenomenal success. You can produce your own email cards without great expense.

Inside Jokes: Jokes also work very well. But not just any jokes. Too many people are tired of the well-traveled routine jokes that land in their inbox from their aunt in Pittsburgh. You can, however, tailor your humor to fit your readers. Create tasteful, inoffensive jokes that appeal specifically to your audience. If you sell educational products, for example, an e-mail with jokes specifically written to appeal to teachers is ideal. Not only will teachers appreciate it, but they will likely forward these jokes to other teachers, who will appreciate the inside humor. This will quickly result in an extensive list of quality leads.

Games:Particularly when marketing to a younger crowd, games are a terrific and relatively inexpensive way to capture attention and build awareness. There are plenty of companies that develop downloadable games that you can post on your Web site.

Group Ideas:If your audience is likely to form a club around its favorite activity you can use it as an opportunity for one person to forward your e-mails to other club members. For example, a golf outfitter could offer to send discounts to the other three members of a golfer’s favorite foursome. An investment newsletter could invite investment club members to sign up their club for investment tips.

Things That Are Worth Their While:People will gladly pass along your information if there’s something in it for them. You can offer a simple incentive program for forwarding an e-mail to ten people, such as a coupon, a fun download, reward points, or something else of value to your audience. One of your advertisers or partners might be happy to provide you with a discount to offer to your subscribers if it drives business its way. One caution: As with any incentive, you risk that your prize is more of a draw than membership to your newsletter. Some participants will only stay on your list long enough to reap the reward and then unsubscribe or ignore future mailings. Rewards will never generate the same committed audience as quality content.

Off-beat Stories: If you intentionally conclude an otherwise business-oriented newsletter with a silly story, you increase the likelihood of having the newsletter, or that specific story, forwarded. The fun story prompts the forwarding of the entire content set, and your marketing messages go along for the ride. You can even build an entire newsletter around such stories. A case in point is Strange but True, a newsletter for human-resources professionals from our client BLR. The newsletter features unusual and entertaining stories that deal with various workplace scenarios, such as a recent story which documented the odd but actual happenings between toll collectors and drivers. Strange but True actually began as a final story in another of BLR’s newsletters, but it became so popular that it demanded its own venue.

Other Popular Favorites:Surveys, contests, cartoons, trivia and polls are all frequently forwarded. A case in point is a Web site called YouThink.com, which offers free blogs and journals. This site has built an ever-growing list of dedicated users, many of whom were first attracted by the fun and entertaining quizzes and trivia games circulated via e-mail.

Matt Blumberg and Michael Mayor are the driving forces behind Return Path, an e-mail performance company. Collaborating with them on this project are their colleagues, e-mail strategists Stephanie A. Miller and Tami Monahan Forman. This article was excerpted from their new book, “Sign Me Up! A Marketer’s Guide to Creating E-mail Newsletters That Build Relationships and Boost Sales (iUniverse Inc., 2005) © 2005 Return Path, Inc. All rights reserved.