There is a fine line between running ads for enough keywords in your paid search account to generate sufficient traffic and running so many that you generate junk traffic - that is, unless you only use exact match (or the equivalent). If you are competing in an environment in which there is excess available keyword inventory, then you can probably get away with only using exact match keywords. In fact, if you can, we recommend it. However, this is usually not the case.

Often, due to strong competition for the top keywords, you will need to use a more broad strategy. This opens you up to the possibility of having your ads displayed for non-relevant searches. But there is a way to fine tune the traffic your ads draw without missing relevant searches.

It's done by using negative keywords.

Negative keywords are keywords you specify that should not be included in search queries that trigger your ad. A common example is the word "free". If you sell a product but you do not want ads for your product being displayed to those looking for something free, then you could set a negative keyword of "free" to prevent it.

For example, let's say you sell an ebook about dog training. You might run paid search ads for search phrases like "dog training", "how to train a dog", "dog training information", etc. But if you don't want your ad to be displayed for a search of "free dog training information", then you would set a negative keyword of "free". In reality, you might want to target that traffic anyway in order to give the visitors a free sample of your work, which will hopefully generate a sale. But that is a topic for another article.

Another example would be if you offer language translation services for documents written in Chinese. If you run ads for the broad match keyword "Chinese translations", chances are very good that you will generate a lot of traffic from people looking to have words translated into Chinese symbols for decorative purposes such as tattoos. If you translate business documents for a living, it really doesn't do you much good to spend your time doing one character translations. So a good negative keyword in this instance would be "tattoo."

You can probably think of some negative keywords at the start that make sense, but as you run your campaign, it really helps to know what keywords people are actually using that trigger your ad at inappropriate times. In Google, you can generate a search query report that will show you exactly what phrases have triggered clicks to your site. As you look through the report, if you see keywords that are not appropriate, then those are keywords that you should add to your account as negative keywords.

Using negative keywords is a way for you to fine-tune the traffic that you drive to your web site via paid search without limiting yourself by using exact match keywords. It is a strategy we definitely recommend you look into because it will improve your campaign return on ad spend by focusing your marketing dollars on more relevant keywords.