Search Engine Roundtable tells us that according to a Google Groups thread there are six factors that determine Google AdWords Quality Score. For the uninformed, Quality Score for Google and the search network is a dynamic metric assigned to each of our keywords. The basis of ad position is based on Quality Score and no longer just on who has the highest bid on that keyword.
So it is imperative to improve our Quality Scores to get the higher rank at lower score. But we must identify what are the factors we can control to effect this Quality Score improvement. The higher a keyword’s Quality Score, the lower its minimum bid and the better its ad position.
As found out by Tamar in the Google Groups thread:
1. CTR: The higher, the better.
2. Account structure: Your keywords should be in “tightly themed ad groups.”
3. Landing Page Quality: More information here.
4. Account history: Your average CTR.
5. Historical CTR of the display URLs in the ad group
6. Other Factors: There are hundreds, but the aforementioned 5 are good enough.
One of the other factors that can improve Quality Score is the loading time of our landing page. There are tips on further improving our Google AdWords Quality Score.