Quality Score is the measured value of keywords used in any Google AdWords campaigns. The value of Quality Score influences the ranking of ads and determines how much minimum bids cost for each keyword. The higher the Quality Score, the higher the chances of getting better ad positions at a lower costs per click.
So in order to improve Quality Scores, we have to look at the following metrics:
1. The click-through rate or the ratio between impressions and number of clicks on Google ads
2. Relevance of keyword with respect to other keywords in the ad group
3. Relevance of keyword and ad to the search query
4. Quality of landing page
Now, the amount of time required to load the whole landing page is now considered as a factor. Although this is not yet an official factor by Google (we have to wait for a formal announcement most likely at AdWords blog) it should be in effect soon. The exact number of seconds is yet to be disclosed and Search Engine Roundtable’s Barry Schwartz isn’t sure how Google will deal with servers with temporary server loading issues.
I hope to hear from Google on this soon.