If you're not familiar with Bing, Microsoft's new venture into search, you will be soon.   Launched just a month ago, Bing has already achieve a 7.3% market share.   While this doesn't compare to Google's 62.8% market share, industry experts agree that Bing poses a significant threat to Google in the future.   Within the past week, Microsoft inked a deal with Yahoo that will result in Bingo search result's appearing on Yahoo.

If you're already doing Google Pay-Per-Click marketing (PPC), it's time to consider Bing as new source.   You can access Bing's advertising center here.