Pay-per-click ads like those available through Google Adwords can be a powerful, regular source of prospects for your products and services. However, whenever new clients have asked me to look at their Google Adwords campaigns, I begin to understand one element in Google's growth to more than a $6 billion market value.

Many entrepreneurs fail to take advantage of Google's mechanisms for making sure that their search engine ads get shown only to those who are logically potential buyers and that the ads encourage such people to click through. As a result, they pay much more than they have to for the exposure, get discouraged about the return on their investment and yet leave the ads running for lack of ideas about how to improve performance.

Don't let it happen to you! Use these tips to keep your costs down and your rewards high.

1. Eliminate countries and languages that do not match what you offer. For instance, if you sell U.S. foreclosure listings, your ads should show only to Google users in the United States and probably only in English. On the other hand, if you have a translation service whose clients can live anywhere in the world, define the countries and languages your ad gets shown to much more widely.

2. Activate Google's ad tracking. It costs you nothing, and enables you to keep an eye on not only your cost per click and click-through ratio, but also which keywords and which ads best lead to your desired result, whether that's a sale, an inquiry for your services or a signup for your newsletter. That way, you can eliminate or try to improve elements that get a lot of clicks or cost a lot but do not get results.

3. Set up negative keywords. If your goal is selling something, why pay for tire kickers and freebie seekers? By defining "free" as a negative keyword (Google has a special button for this), you can keep many of them from clicking on your ads.

Equally important, think through alternate and unwanted meanings of your keywords and add negative keywords to prevent your ads from showing to wildly inappropriate visitors. For instance, type "cattle branding" into Google and you'll see ads for business branding services. Those advertisers' click-through rates will improve when they add "cattle" as a negative keyword.

4. Delete keywords and ads that are not working. Because Google's system rewards a better click-through rate with higher ad placement and lower costs, you are paying Google more than necessary when you leave poorly performing elements running. Periodically clean out your losers.

5. Send people to a landing page that makes perfect sense. People click on search engine ads to learn more about whatever was featured in the ad. It seems logical that they'd look around from your home page for whatever interested them in the ad, but that's wrong. Searchers are impatient. So if your search engine ad mentions a software demo, do not send them to your company's home page. Send them to the exact page from which they can access the demo.

When you manage your Google Adwords campaigns according to these guidelines, you'll be paying less to get a much more satisfying response.