shuzhen

I strongly advise all advertisers and especially those who use broad match versions of keywords to log in and check your spending. Some recent changes at Google have caused the traffic and clicks on some keywords to increase dramatically. If you're not sure if you use broad match, since it is the default you would be.

This has not affected all advertisers or all subjects; however, since it can make an enormous difference in spending in a very short amount of time I felt it prudent to let advertisers know it would be wise to check and monitor all accounts.

See the thread Watch Spending When Using Broad Match and the links to other sites within that thread. It contains additional information and tips to best control spending and ad targeting.