For those who are involved in pay-per-click (PPC) advertising, AdWords is the big player. It is the main advertising avenue for Google.
AdWords advice focuses on something called Quality Score. If you have a good quality score, then your ads get better placement and you pay less. One of the biggest factors in quality score is, supposedly, a high click-through rate (CTR). That's when a high percentage of people click on your ads, through to your website.
Below is a screen shot from one of my ad groups showing the top seven keywords. I've blurred the bids and the cost both to protect my bidding and to minimize offense to the folks at Google.
In my experience, 5% is a pretty good CTR. Here, four of the top seven have CTR over 10%. Despite that, the quality scores are very low. As Google describes it: "On this scale, 1 is the lowest rating, while 10 is the highest. 1-4 corresponds with Poor, 5-7 with OK, and 8-10 with Great."
So my keyword with an amazing 14% CTR has a quality score of 4 out of 10, which, in Google's description is "poor."
For those who are really into this, the shot is taken with the date range set to "all time". I've been running this campaign for about 2 months. I don't have a past bad history with the relevant keywords. To the extent that I have a history with related keywords, it's a good history. The landing page is highly relevant. The keywords are all "phrase-match" and the search term report shows more than half the clicks were "exact match", and all of those had even higher CTR.
I'm very fond of AdWords and I'll keep using it, but we're not getting the whole story about quality score.