Google Adwords has some new and upcoming changes in there AdWords department.
Starting today, and over the coming weeks, we'll be implementing an ads quality change designed to show fewer ads on queries for which our users might prefer not to see them and more ads on queries for which ads are useful. The impact of this change will vary from advertiser to advertiser, so we wanted to give you a heads-up and suggest that you keep an eye on your keyword performance over the next few weeks.
Read more:
Inside AdWords 
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