Much have been discussed about what constitutes to the quality score of an ad for a given keyword. Some people said it was all about relevance, some said landing page was the most important factor and others claimed that a high bid will lead to a high quality score.

If you are not sure how the quality score is calculated and what are the factors that affect it, take your ten minutes to watch the video below and hear what Google says about their quality score algorithm. Although this is not a fresh video, what it tells is still valid.

In the video below, Hal Varian, Chief Economist at Google, explains the factors that constitute to quality score and how the ads from different advertisers are listed. It will clear some misunderstandings about the quality score for sure.