Paid-placement search engine listings, like those at Goto.com, are great for effective, targeted and low-cost traffic for your website. That's why so many people are using them, driving up prices of even obscure terms in bidding. Google's Self-Service Advertising System, called "Google AdWords," and "Jeeves Text Sponsorship Network" are two similar services you should add to your list of places to advertise.
They can each be effective ways to advertise your site or product at a low cost, with added benefit of being CPM-based, meaning you pay according to number of impressions of your ad shown rather than number of clicks.
Relatively new, Google has decided to offer an easy way to get your site in their search result pages without spending days or weeks setting up a banner advertising campaign with them. Unlike a paid submission, you are not paying to have your site listed in Google search results, but to have your ad appear alongside search results in a special "Sponsored Links" section. Here, to right of search results, your link and a short description can appear along with up to 8 others for only a few dollars per thousand impressions.
Because you will be paying $8 to $15 per thousand impressions, or views of your ad, at Google, you'll need a high click-through ratio in order to justify spending money and to get traffic to your website. Choosing keywords to purchase advertising on shouldn't be too hard. Assuming you track it, start with phrases people are already using to find your website in search engines. Add to that any other words you want to buy a listing in that are related to your site, more specific better. You can expect a click-through ratio 3 or 4 times higher for very specific terms, like "free business cards," as opposed to very general terms, such as "business".
Once you've chosen keywords to purchase advertising on, write ads for each one. You may only need several ads for different sets of keywords (such as one ad to use for both "free business cards" and "color business cards" and "business cards"), but you will probably get better results if you don't use same ad on all terms you are purchasing listings for.
While your ad headline and content are limited to very few words, you should remember basic rules for writing ads. Use search engine term in headline of ad so that surfer knows your ad is relevant to their search. Make sure reason to visit your site is clearly visible. When your ad is read, surfer should know what you have to offer them.