New pay-for-performance search listings, offered through companies like Overture and Google, have become so popular with advertisers so quickly that they're being credited with a) single-handedly reviving the fortunes of major Internet companies, and b) hastening the demise of the banner ad.

An effective complement to both search engine optimization and targeted direct marketing campaigns such as e-mail and direct mail, keyword programs are a highly cost-efficient method of capturing measurable response from prospects actively seeking information on your particular category of product or service. Here are some tips for making the most of your keyword buys:

1. Don't link your ad or sponsored link to your home page. Sure, it's an additional expense to design and host a custom landing page or microsite (perhaps as much as you're paying for the keywords alone), but it's worth it. A well-designed landing page will convert many more click-throughs to actual leads.

2. Sell the offer, not the product. In your ad, tailor your copy to the specific search term, and mention the offer prominently. For example: "Application Integration: free white paper, CD-ROM, more." Success with keyword programs is about generating real, measurable leads, not just click-throughs, and the best way to capture contact information from prospects is to get them to ask for something.

3. Test as many search terms as the search vendor will allow. Sometimes, the words or phrases that become top-performers are what you expected all along, often they're not. Measure performance after a couple of weeks, dump the losers, and add variations on the terms that are performing best. At their most effective, keyword programs require a constant process of monitoring, testing, and refining.

4. Don't forego sponsoring specific terms just because you're already showing up in top search positions already. Here's why: 1) sponsored links may complement or reinforce existing search listings, 2) you can't control the text in the listing, but you can write the ad (so it's likely to be more effective in generating response), 3) if people click on the listing, they go to a random page on your site; if they click on your ad, they go to a landing page (see #1, above).

5. Don't be afraid to test a particular search term or phrase just because it's expensive, or popular, or because you're likely to "burn through your budget" too quickly. You can always limit your spending on a given term, and you may find, in testing it, that it yields higher conversion rates -- meaning a lower cost per lead than other, seemingly more "affordable" keywords.