Your site must show up in most of the top 20 search engines, whether human-powered portals like Yahoo! and MSN or spider-crawlers like Google and AskJeeves — preferably placed high in the listings.

Consider This - Very few of online surfers looking for a particular topic or company's Web site will actually type the URL into their browsers, according to a recent Jupiter Media Metrix survey. That means many Web surfers head right for a search engine to find what they want. And when they get a results page on their search, very few people click past the results shown on the first few pages.

Yet business owners typically invest less than 2% of their marketing budgets in securing highly placed listings. It's time to take the bull by the horns.

"The biggest issue with search engine marketing is that it keeps changing as the algorithms and rankings change," says Orville Wright, professor of marketing at the James Madison University in Harrisonburg, Va. Just when you think you have a handle on it, you don't.

As a result, Wright and other experts suggest you concentrate on honing what doesn't change: the keyword search phrases and meta tags (HTML tags that sum up information about each Web page) that are picked up by the engines. And most important of all - well written visible content.

'Get inside heads of customers'

"You need to figure out how people were looking for you when they stumble onto your site," says Chris Grant, Web analyst at Fry Multimedia in Ann Arbor, Mich. "To get the phrases that work, you need to get inside the heads of your customers and figure out how they see your business."

The name of this game is the quality and kind of visitors you draw, not the volume of traffic. If you sell ski trips to Vermont slopes, and your keywords are "ski" or "ski package," you'll attract hundreds of disappointed vacationers who were looking for Aspen or Gstaad.

When selecting search phrases, search engine guru Danny Sullivan of Search Engine Watch says you're not just trying to make the right submissions or get top rankings. What you're trying to do is improve the odds of how your site is "seen" by the engines so the audience you want can find you.

Some tips to identifying effective search phrases:

1. Brainstorm with senior staff and salespeople to come up with words and phrases that are the DNA of your business.

2. Visit competitor sites to get ideas — don't use their exact phrases. Right-click on their pages and select "View Source" to see which keywords they use.

3. Ask customers what words they use to talk about your products.

4. Review Web logs to find phrases and search engines that delivered visitors who registered and/or purchased.

5. Rely on services like Wordtracker to monitor popular phrases.

This is an ongoing process. To keep directing the right traffic, you must continually update and refine keywords. You can be surprised at what works.

Link Exchanges often help

Some engines will rank you higher if you're linked to other sites. Try developing relationships with other businesses and exchange links. Then check the Web logs to see if it's made a difference. Also, beware of "frames" on your pages, in which one page is inside of another on your site. Spider search engines sometimes overlook framed pages. If your site depends on frames, make sure your meta tags are thorough and diverse.

You can automate the tedious chores of multiple engine registrations and submissions with inexpensive software like Submit It! or Traffic Builder. That way, you fill in your information only once while the software takes care of the rest.

Next, you might need to be patient. You can't expect immediate results with free search engine placement. It can take anywhere from a lucky week to three months or more for a search engine to update the database after you submit.

Paying for clicks might be worth it

When you pay for placement, the process gets speedier; this is why search engine companies like Overture (formerly GoTo) are growing even in a down economy. "Pay-for-placement search engines usually employ an auction model where the highest displayed ranking goes to the highest bidder." says Greg Katz, director of operations at IMT Strategies, a Stamford, Conn., marketing consultant.

Unlike advertising and other marketing, you typically pay for placement only when it works — about 5 cents per click — so you can quickly decide what's worth the expense.

By nature, search engines are tricky, changeable things, as programmers continually filter spam and work to keep rankings credible and relevant. The time and attention such marketing demands is best handled by automated software or an outsourced provider. But in this tough climate, given the cost and the possible payoff, search engines add up to the best bang you can find for your marketing buck.