Quality Score (QS) is a value that Google uses to determine how relevant your keywords, ads and landing pages are to a user's search query. It is like a keyword's report card. It is important because it influences the position at which an ad shows and how much you pay-per-click. It is a number between 1 and 10 with 10 being the best.
Google doesn't store historical Quality Score data. You can't see what the Quality Score was for a keyword a month ago.
In your AdWords account, Quality Score is only visible at the keyword level which makes it difficult to scrutinize and take action. The Quality Score Tracker:
We know change in Quality Score impacts statistics like bids, avg. cost-per-click and traffic. But how do you see the correlation? The tracker lets you:
Analyze the general health of your account by seeing how keywords are distributed in your account.
We keep an eye on your highest spending keywords. You'll get a notification if the Quality Score of a keyword drops suddenly.