The whole idea behind a negative match is to cut out irrelevant impressions, and possible clicks, on your advertisements. Irrelevant clicks are similar to unwanted customers, or even shoplifters coming to your store. Of course, if you’re running a large campaign thats generating a lot of traffic, it becomes difficult to monitor your traffic.

This brings me to my principle argument. Negative matching is not always a helpful procedure, and in fact, if done wrong will ultimately be damaging to your campaign bottom line. For instance, if I’m selling goods for a merchant who sells organic products, but does not stock pumpkin seeds, I will most likely have to use negative matching for certain keywords. I’ve structured my account in such a way that I have made one campaign for organic skin products, and another for various organic food products. Now to the negative matching. Instead of running negative matches on [pumpkin seeds], [cheap pumpkin seeds], and [what are pumpkin seeds], I simply need to broad match the negative keyword ‘pumpkin’ on a campaign level.

The more complex negative matching happens when you have conflicting keywords in similar campaigns. For instance, your food campaign contains different brands of poppy seeds, as well as various brands of sunflower seeds. ‘Organix’ has both types of seeds, while ‘Natures Way’ has only sunflower seeds. Broad negative matching on a campaign level, for either the brand, or product in this case creates a problem. In this situation negative matching should ideally be done on an ad group level, using broad match types.

For a campaign with 100 000 keywords though, where the merchant has a vast product line, this process is very time consuming. The ideal is that you want to cover the long tail of negative matches, giving you a high CTR, with relevant copy, and a great landing page for every keyword you’re running, but more often than not, the time requirements of these bigger campaigns do not allow for this. If you don’t have the time for group level negative matching, then the second best thing is to look at your high density and high traffic keywords…either before or after the campaign has launched.

If it’s before the campaign launch, you can use Google’s traffic estimator tool (allows for bulk operations), and then run your high traffic keywords through the keyword tool. In this case you can do some head negative matching pretty quickly for all your high traffic terms.

If you want to do negative matching afterwards, take your existing information on your high impression keywords as a pointer of where the work needs to be done.

Lastly, with regards to negative matching for newly generated keywords. Personally, I feel that instead of exact negative matching all keyword terms that are irrelevant, I would firstly look for patterns in your irrelevant keywords that you could generate strong broad negative matches for. This will get to the root of the word, and avoid any possible misspellings/variations that could come up the next time you do new keyword research. By simply running exact negative matches, you are not accounting for the sheer amount of semantic variation that Google has to deal with on a day to day basis.

Any other thoughts on improving your CTR through negative matching?