Here's the puzzle I'm having: A while back I created an ad, and had just 2 or 3 very closely related exact match keywords in it. These words instantly came through with a QS of 7. A few other keywords that were used returned having low search volume, and last time i deleted them because of that. Now we deleted that ad because we thought we weren't going to be selling the product for that ad anymore, but now a couple weeks later, my bosses decided to go the exact opposite direction and want to market for this product very aggressively. So I rewrote the ad practically identically, making sure the keyword displays in the headline, the ad copy, and the display URL, and this time put in some more keywords, again, still very very tight, and this time I also am keeping the low search volume keywords. I am targeting the same landing page. I'm using some exact match keywords but also some modified broad match keywords. This time around though, I can't get any of the keywords to rank higher than a QS of 5, even though some of these were the same keywords used before, for the same landing page, for an almost identical ad copy. The only differences between then and now is I am now doing ad copy split testing, having the one identical ad copy, and a 2nd ad copy that's totally different, and I am keeping the low search volume keywords. I highly doubt that the 2 ads are what is killing my QS. So is keeping the low search volume keywords having some impact on my quality score even for the other keywords? Is Google looking down on my account for keeping those keywords in there? I would kill them, but I tested the keywords and the ads are still actually displaying despite what Google says, so it doesn't make sense to kill the keywords. If I kill these words, what kind of effect can I expect it to have on the ad group, if any?