I’ve read in places about display URLs affecting quality scores. However, the discussion always surrounded around how a display URL affects the clickthrough rate of an ad, which in turn, is used to calculate quality. The relationship was presented as an indirect one. Anyone interested in knowing the nitty-gritty of quality scores will be interested in knowing that there is also a direct relationship between quality scores and display URLs. This fact popped up when I noticed that one of my favorite AdWords help pages was recently edited. The help page discusses the factors that go into the different quality scores Google uses, and it has two points added. First for calculating a keywords minimum bid, it states that one factor is “the historical CTR of the display URLs in the ad group.” Second for a keyword’s ad position it also states that the display URL is a factor. Before and after shots of the change are shown below, click to get a full image.

AdWords Help Page - Before

AdWords Help Page - After

What Does it All Mean?

Attached to your display URL, somewhere in Google’s system, is a historical CTR. It’s kind of a strange fact when you take into consideration that an entire ad is what gets clicked, not a display URL – that’s just one factor – but AdWords does assign CTRs to display URLs. This means if you had poorly performing ads in the past that had the same display URL, and you start up a new ad with the same display URL, the quality of that new ad will be negatively affected because of the other ads’ poor performance history. Maybe those ads didn’t perform poorly because of their display URL but because of their descriptive text? Doesn’t matter.

It’s hard to imagine this factor having heavy weighting. I don’t think I’d go out of my way to change a display URL because some of my other ads had poor performance. But for those of you who are absolutely scrupulous about covering every base, you might consider it.

The reason AdWords might consider display URLs is to detect if search engine users are avoiding (or are attracted to) a certain site. Of course, if Google users were avoiding a site, it’d seem that the ad would suffer anyways from a poor clickthrough rate and that the account on a whole would suffer because of poor CTRs. If the display URL factor was an important one, you might imagine a couple scenarios where it’d really make a difference:

1. Accounts containing multiple domains (this isn’t typically done unless the sites are highly related anyways, and I think Google discourages it).
2. Sites that have good natural listings. If you’ve already visited a site’s natural listing, you might avoid its paid listing because you’ve already seen what they’re offering.

Since you really don’t see the individual factors that contribute to overall quality scores, I’m just going to say - cheers, here’s to a little more Google mystery.