Information used to be presented with the broad-brush approach. Writers who wrote articles or books or other forms of content had to write things generically to appeal to a broad spectrum of potential readers. Writers seeking information on their careers might buy a book on how to write, but not specifically on how to market an article to a magazine. Parents bought books on childrearing, not on how to deal with a recently diagnosed case of autism.

The Internet changed a lot of things in our culture, including creating a flurry of interest in very narrow topics. Visit the web and you can find out how to market your article on video games to a gaming website or how to talk to your child's teacher about his recently diagnosed Asperger's syndrome.

If TV brought to us the concept of broadcasting, then the Internet is responsible for the concept of narrow-casting, that is, fine-tuning information to appeal to very small but specific segments of the public.

So what does that mean for an enterprising writer? It means that expertise and writing projects that once would have been roundly rejected can now not only find utility and purpose, they can actually be sold.

Here's how it works.

This is based on the assumption that you (like everyone else) have particular in-depth knowledge of many subjects. Whether it's catching feral cats, raising orchids, deep-frying turkey, paying down credit card debt, opening a daycare center, or explaining how pacemakers work, most of us can't get through life without acquiring some very in-depth knowledge about some very narrow subjects.

If you can't think of what you might know in-depth consider your education, your jobs, your friends, your hobbies, and projects you've been involved with through your family, friends, and clubs.

Don't worry if this information is too obscure or too off-the-beaten path. Just start to accumulate a list.

If you're a writer, you're also likely to be an able researcher, so you can fill in gaps in your knowledge of fly fishing or recommending cures for snoring. You can even get expertise in a whole new area by talking to experts and conducting your own online research.

In the Internet world, each of these subjects is called a niche. Many niches are actively sought by Internet denizens who are out trolling constantly for information.

Take celebrity sites. There are always legions of Internet people seeking the latest news on Britney Spears. Now raise your sites a little more. There are also people eager to get new quilting patterns, learn to speak Portuguese, find a great vacation getaway in Italy, or write a killer resume.

Each of those is a niche. As a writer, you can develop what are called information products to serve that niche. For example, take the niche of job seekers. An electronic book or e-book on resume writing might appeal to them. You might also write about some unusual job search tactics, how to shine in a job interview, and finding jobs that aren't advertised.

In other words, every niche has lots and lots of potential information products. And don't dismiss physical products and more traditional services. Staying in the job search niche, you could sell physical products (resume-writing software, briefcases, calendars, expensive pens or other “accessories” for the job interview) or services (resume writing, job placement).

While all of these are interesting and many of them are viable enough to be profitable (if done correctly), no area is as lucrative as information marketing. You may create an information product for sale; it can be electronic or a physical product on a niche topic.

What kind of products can you sell? E-books are popular; these are downloadable manuscripts. With today's digital printing technology, you can also publish and sell a physical book almost as easily. (Ironically, e-books tend to have a higher profit margin and sell for more money.) You can sell audios, such as interviews with experts. You can sell videos, which are particularly useful on how-to subjects like how to knit or how to transform your home computer into a sound studio.

Internet marketers have known about niche marketing for a while but the biggest stumbling block for many of them is not the marketplace or the ideas or finding customers. It's the writing!

That's why writers have a great advantage. Internet marketing can be learned (there are many great resources) but writing is a much harder skill to master. Any writer who can successfully identify viable niches and then create products for that niche can become a highly successful Internet marketer by applying his or her writing skills to a new marketplace (with new rules).