Today I have a video explaining all about Google AdWords Quality score. The only people who really know about AdWords quality score are the technicians who create the AdWords program. Every time I have ever spoken with a live person from Google, they seem to be in the dark like the rest of us as for as Quality score is concerned.
What we do know is that at least 50% of the quality score is made up of the click through rate (CTR), so it makes sense to have a well optimised campaign with ad groups with a tight theme of keywords with a well written ad and sending the visitor to a page with relevant information.
I hope this video makes sense to you.