When revenue is uncertain and ROI is even more important than usual, any advertising that can precisely measure and track results is especially valuable. Online, that's very doable. You can see where your money's going, what you should invest in and what you should change.
In fact, companies that invest intelligently in growing their business, even in softer markets, will be able to leapfrog their competition, who might be much less efficient with their ad spend or turn it off altogether.
SEM campaigns have always been attractive, since they give you crystal-clear metrics on how much you're spending for how many eyeballs and clicks on specific keywords and creatives. And Google Website Optimizer shows you exactly which changes will improve (or reduce) your online conversions—however you define them.

