What are Negative Keywords?: Negative Keywords are those handy little gems that help us filter out the possibility of attracting a non qualified user to the site. When certain keywords are designated as Negative Keywords, then Google will prevent your keywords from triggering your ads if that negative keyword was included in the search query.

How to use Negative Keywords: The effectiveness of your negative keyword list relies on the structure of your account. You can have negative keywords entered at the Account Level or at the Campaign Level. For example, let's say you're operating a website that provides clean jokes and stories for people to read. In this instance, an Account Level negative keyword list containing negative keywords like "nasty, dirty, sexy ..." would be appropriate. Now let's assume you run a Costume site selling costumes for many occasions. You could have a campaign set up for Children's Halloween Costumes and a campaign for Adult Sexy Costumes. In this case you should put negative keywords at the Campaign Level of the Children's Halloween Costumes like "sexy, adult, revealing, etc." to prevent those keywords from triggering when kids are searching for Halloween costumes. Like wise, in your Adult Sexy Costumes campaign, you should enter Campaign Level Negative Keywords like "child, children, kids, etc." to prevent any of your keywords from triggering as the result of children searching for costumes.

Negative Keyword Match Types: Negative keywords also have match types just like your regular keywords. There is negative-broad, negative-phrase and negative-exact. When using negative keywords it's important that you use the correct form of the negative keyword. For best results, to avoid Google from mapping your negative keyword to multiple possibilites with their extended broad match, enter your negative keywords as negative-exact to ensure that the only way your ad won't trigger is by someone typing in the negative keyword exactly as you entered it.

In Summary: Negative Keywords when used correctly will save you money, improve your online ROI from your pay per click accounts and present your site / products in a better light to all prospects searching for your products / service.