Robert Curtis Allen already knew plenty about pipes and drains when he bought his father's Houston-based Allen Plumbing Co. in 1989. But it wasn't long before he realized how little he knew about pricing and marketing. To help educate himself, Allen, an early and avid user of America Online, teamed up with a fellow plumber and cyberbuddy, Kathy Love of West Columbia, S.C., to start the Plumbers Discussion List in 1995.

The Plumbers List is just one of hundreds of E-mail discussion groups, also called listserves, that are proliferating in cyberspace on almost every imaginable topic. Members with a common interest sign up for the lists by E-mail, then exchange ideas, make comments, and ask each other questions by sending E-mail messages, called "posts," to a central server. The messages are either automatically sent to all the list members or screened first by a moderator. Members usually learn about a given list by word of mouth or discover it on a Web-based directory, such as Liszt (www.liszt.com), where they search for lists sorted by topic, read list descriptions, and get directions for subscribing (see table).

In Allen's case, trading business tips, product reviews, and industry gossip on the 420-member Plumbers List really paid off. Marketing suggestions from other plumbers helped boost gross sales 40% in the list's first year and 30% the next, he says. He learned about a better way to price his services, too. "I wouldn't be driving this new truck or have any employees today if it weren't for the Plumbers List," he adds.

Sure, Web sites receive most of the buzz. But E-mail discussion lists are one of the Net's best -- and least-known -- resources for small businesses, functioning much like a combination brain trust, support group, news service, and professional seminar. "Online discussion lists are invaluable for sharing information, especially for entrepreneurs, because the tips come from fellow entrepreneurs in the trenches," observes Steve O'Keefe, a New Orleans-based Internet expert and author of Publicity on the Internet and the syndicated column "Online Marketing."

SPAM-PROOF. For convenience, listserves beat out their closest cousin, the Usenet newsgroups -- Net-based bulletin boards. They're also far less prone to blatant marketing pitches, or "spam," because many lists have rules prohibiting them. For communication, E-mail lists can also be more efficient than a live online chat or a phone call, giving you time to craft your responses carefully. Also, you can archive or print out messages for later reference.

For many entrepreneurs, discussion lists are potent marketing tools. Although direct sales pitches are a no-no, posting to a list allows you to show off your expertise and lets potential customers get to know you and your company's services. Lorilyn Bailey quit her day job last April to focus on building her Lormax Communications, which publishes self-help books and provides experts for media interviews. She says about 75% of her clients learned about her through the informative posts she makes to the Publishers Marketing Assn. list, consisting of fellow publishers. Posting "gave people an opportunity to know me and trust me," she says. "I would not be in business if it weren't for that group."

Other business owners join lists for help answering specific business or technical questions. Sandra Jacobs, business-development manager for 160-employee Telescan Inc., a financial-services information firm in Houston, needed help handling big clients who are slow to pay. Members of the Internet Sales Moderated Discussion List, which discusses how to sell products and services online, offered concrete, useful advice. "You see how other people dealt with the same situation you have," she says.

NARROW FOCUS. E-mail discussion groups cover just about every subject under the sun, from accounting to zoology. A recent perusal of Liszt turned up 178 business lists, 298 culture lists, and 366 recreation lists. Some business lists are general, such as TalkBiz, while others focus narrowly, such as Can-AccTech, where Canadian accountants discuss software tips.

Business owners who use lists tend to subscribe to more than one. Julia Lyons-Wood, 30, whose year-old Calgary-based Investigative Marketing Services does consumer research in the U.S. and Canada, subscribes to five different lists, including Women Talk Business for general business topics and Market Think Digest, which discusses marketing.

Lists also vary in tone and purpose. Some are chatty and friendly; some are bare-bones and technical; others tend toward the philosophical. There are small private lists -- for a company's board members or a single college class, for example -- and huge public lists, like the 85,000-member LinkExchange list, which discusses Internet marketing.

Discussion lists can ease the isolation of home-based and solo practitioners. Bailey, who recently moved to Raleigh, N.C., from Rochester, N.Y., and works at home, finds the publisher's list helps make up for her limited social network: "The list is like the water cooler: You share jokes, you gossip."

In a crisis, list members sometimes give comforting moral support. Last summer, herb grower Lucinda Jenkins saw her Glenbrook Farm threatened by fires raging through Suwannee County, Fla. Distraught, she turned to the Business Women Connected list, writing: "My heart is in my throat as I look out the window." Replies came immediately: "Our prayers are with you," said one. Soon, rain broke over Suwannee County, and, Jenkins says, "It felt like divine intervention."

How do you find a list that's right for you? For starters, go to one of the list directories. Peruse the lists by category or plug in a topic, such as "knitting" or "E-commerce," and see what comes up. After following directions to subscribe, you'll usually receive a "welcome" message explaining list rules and how to "unsubscribe" if you change your mind. Be sure to save this message. Take a few days just to "lurk" on the list, getting a feel for the group. Then post a message and wait for the responses.

The biggest problem with joining lists is managing the influx of E-mail. Some high-volume lists let you subscribe to a digest version, which delivers an entire day's (or week's) posts in one E-mail message. Also, most E-mail programs have filters that can be set up to delete E-mail automatically or file it into folders, according to sender, subject, or other criteria. If you still feel overwhelmed, set up a separate E-mail account to receive list posts at a free service such as Yahoo! or Hotmail.

While spam is usually taboo, nearly all lists let you subtly promote your business by signing off with a so-called signature, or sig, file. It usually includes contact information, a Web-site URL, and maybe a brief business description so list members get to know who you are and how to find you.

TIME TRAP? What's sometimes better than joining a list? Starting one of your own. A moderator who appears in a list every day gets an extra measure of credibility. Adam Boettiger says that running the list Internet Marketing has brought some $500,000 of business to Portland (Ore.)-based Internet advertising firm eyescream interactive inc., where he is vice-president of business development.

To start your own list, you'll need list-management software and space on a server, available from such companies as L-Soft International Inc. in Landover, Md., or SparkNET Interactive in Green Bay, Wis. Majordomo, a free listserve program, is distributed by Great Circle Associates Inc. of Mountain View, Calif. Some companies offer free hosting as well, but without service and support. Be forewarned: Moderating a high-volume list can be time-consuming. It takes Boettiger, who moderates the Internet Marketing list, about two hours a day to screen about 300 E-mail messages.

Otherwise, hosting services charge from as little as $10 per month for a low-volume noncommercial list with no tech support to as much as $22,000 for a huge commercial list with management bells and whistles. Some companies use sponsors to help defray the cost, while others consider it a marketing expense.

So, for a new perspective on the Net, look no further than your E-mail box. Whether you own a list or join someone else's, it could be just the boost your business needs. You might even end up like plumber Allen -- flush.

By Edith Hill Updike in New York

This article was originally published in the Nov. 9, 1998 print edition of Business Week's Enterprise.

To: MARKET RESEARCH