The Lowdown on Pay-Per-Click Advertising Pay-per-click advertising can bring a stampede of shoppers to your site, but make sure your keyword performance is profitable.

Pay-per-click delivers serious shoppers to your site instantly, and it's cost-effective if done right. Play smart with the three leading search engines--Google, MSN and Yahoo!--to drive in new customers without blowing your budget.

Why advertise on all three? Not only do they get the lion's share of search engine traffic, but they also feed their PPC ads to different sites. For example, Google feeds AOL, and Yahoo! feeds CNN.com. (MSN has not yet announced its distribution partners.) With different audiences and advertisers, your ad's performance can vary on each engine.

The minimum bid on Google AdWordsis 1 cent per click. MSN Keywordsis 5 cents per click, and Yahoo! Sponsored Searchis 10 cents per click. All have a $5 account activation fee. The highest bid gets the highest position on Yahoo!, whereas Google and MSN give the highest position to the advertiser with the highest bid and the highest click-through rate.