Re: Quality Score
I do believe that Google used to look very much into the headers, title tags and meta tags of a landing page, however they have recently changed be more about the relevant content to your keywords and ads. They also check to see that your site is trustworthy and easy to navigate.
I still think that they do look at this to help increase the relevance but it isn't as big a part of their check-list as it was a year or so ago.
Even if it wasn't relevant any more it still wouldn't hurt to have similar headers, title tags and meta tags to your keywords.
Re: Quality Score[ Edited ]
August 2014 - last edited August 2014
Relevance is more than a <H1> KW, we must pay attention to other QS factors like - in detail - landing page experience, if you find a really bad Landing Page with all the items you mentioned: " title tags and meta tags", and your search query is all around the site but the load time, the mobile compatibility, navigation, etc. are so bad, what would you do as a visitor?. Maybe, we have to think as users to improve our QS, not only as Robots trying to find technical secrets.
Re: Quality Score
Quality Score is calculated based on the three components, namely Expected Click-Through Rate, Ad Relevance and Landing Page Experience. When you are adding a new keyword to your AdWords account, a historical CTR of the keyword will be taken into account.
Google AdWords system allow us to see how these three components are been rated for each and every keyword. Rating will be like Below Average, Average and Above Average for all the three components of Quality Score.
Your query regarding keywords in headers, title tags and meta tags, will fall onto the third component, which is Landing Page Experience. This is again fallen into four major components, namely, Relevancy, Transparency, Ease of Navigation and Page Load Time.
For more information on how to optimize Landing Page Experience, visit https://support.google.com/adwords/answer/2404197?hl=en&ref_topic=3122882
As a best practice, inserting keywords, I mean the exact keywords through URL parameters on server-side to Headers(Heading like text on Landing Pages) as well as Title Tags may have a positive effect on Relevancy. But adding keywords in meta tags, will not improve the Quality Score. For additional reference, kindly visit https://www.en.adwords-community.com/t5/Advanced-Features/Dynamic-Destination-URL/td-p/200110