When used correctly, the beauty of negative matching is that advertisers can filter out keywords when they do not want their ads shown, Prestipino writes. "If I sell a white paper on selecting domain names and want to attract aspiring domainers, I might bid on the term 'domainer' with a broad match ad type, he writes. "However, I know through my keyword research that I don't want to receive traffic for 'lazy domainer,' a name of a popular blog on domaining. In that case, I would add 'lazy' to my keyword list. Over time, and through trial and error, I have learned that it's absolutely essential to have negative keywords if you have a lot of broad/phrase match keywords in your campaign."