When determining the minimum CPC you should pay for a keyword (and also wether to make your keyword active or inactive in Google adwords or not) they evaluate the quality of your ad content (amongst other things).
Google explain the quality score in their help as:
“Your Quality Score reflects your keyword’s CTR and the relevance of your ad text and landing page. Keywords with high Quality Scores are more relevant for users, more effective for your ad campaigns, and have lower minimum CPC bids. ”
When evaluating wether to make one of your keywords active or inactive Google combines your Maximum CPC and your ads Qaulity score to determine of the keyword status.
Google explain the keyword status concept in the AdWords Help Center - What does my keyword’s status mean?
Of course your Maximum CPC is obvious, but your quality score is not. But there is a hidden column that you can display to make everythng clear…..
