I agree that keywords with a low Quality Score are often much better candidates for ad group expansion than keywords with a high Quality Score. I also agree there is generally a correlation between Quality Score and conversion. However, I think a stronger correlation exists between that of Quality Score and CTR, and if I am right in assuming that a higher CTR generally means a higher Quality Score, I would not feel confident saying that a higher CTR necessarily leads to a higher number of conversions.

In my opinion, Quality Score should be seen as an indicator of a successful campaign, rather than the cause of a successful campaign. I don’t think Quality Score should be the end goal of PPC management; I think relevancy itself should be. If high keyword / ad group relevancy is your end goal, Quality Score will naturally follow. But if Quality Score is your end goal, there is a danger of focusing too heavily on improving CTR, and in doing so opening up your messages too widely, making them unqualified, unfocused and unoptimised for conversion.

So although keywords with a Quality Score of 5 will rarely outperform keywords with a Quality Score of 10 (in terms of ROI), and you’re completely right that Quality Score can be useful in identifying areas for ad group tightening, I think Quality Score should only be used as a rough guide in PPC management. Relevancy itself, in my opinion, should be the focus, and everything else will follow.

Thanks for commenting. Appreciate the feedback and hope you enjoy the blog!

I think this post has an interesting tact, but seems to risk putting the cart in front of the horse a little bit. What I mean is, relevance is primarily an input to Quality Score, so the only reason to split up keywords into smaller ad groups is to improve Quality Score. (There is a slight chance you’d want to do it to write ads which resulted in higher conversion rates, but the correlation between QS and conversion is usually quite high. You comment about targeting a better landing page obviously makes sense too.)

All I’m suggesting is that before anyone should consider all this, they should check whether or not they need to improve Quality Score on the keywords in question. If so, then tightening up ad groups and writing more specific and click-worthy copy is a great idea. Otherwise, doesn’t seem worth any effort.

Looking forward to my new subscription to your blog.