For most companies (that probably means yours), the World Wide Web hasn’t been the fountain of cash predicted. But the Web is still an inexpensive way to boost your bottom line, namely through marketing.

First, the bad news.

Certainly Web-based sales have proven lucrative for niche companies, such as those with vast inventories of hard-to-find, rarely stocked goods. But for most, the Web has yet to turn big profits.

Certainly the consumer-friendly Web has changed buying, selling and communication patterns. But as the burst dot-com bubble demonstrated, the Web has been more bust than boom for entrepreneurs and investors, many of whom lost their proverbial and virtual shirts.

Now, the good news.

Web sites are rapidly becoming the 21st century’s business card, brochure, catalog, customer-service center and marketing department rolled into one. A Web site might not be the best place to conduct your business. But it can provide two essential business functions: identity and service.

A Web site can effectively reach existing markets and even markets previously beyond your reach. Just as importantly, the buying public increasingly demands businesses have Web sites. A new prospect is as likely to ask, “What’s your Web site?” as to ask, “What’s your phone number?”

Virtually every interactive function you perform with customers and prospects can be provided to some degree by a Web site—often faster, cheaper and more powerfully. Answering customer questions, tracking orders, communicating with clients and many more aspects of customer service call all be delivered via a Web site.

Keep this in mind, however: Marketing and customer service on the Web are no different than marketing and customer service offline. The same fundamentals apply.