FEES AND SERVICES . Subject to Section 15 herein, the Service is provided without charge to You for up to 5 million pageviews per month per account, and if You have an active Adwords campaign in good standing, the Service is provided without charge to You without a pageview limitation.
I don't see the problem. If I had 5 million pageviews per month I guess I could afford to have an active AdWords campaign without much problems.
If you exceed 5 million pageviews, they don't cut you off, they just compile your statistics once per day instead of multiple times throughout the day.