Overture uses keyword stemming in all of their match options. Keyword stemming is a grouping of keywords by misspellings, plural/singular variations, and the exact keyword.

The keyword ‘pay per click management’ would be stemmed to include ‘pay per click managing’, ‘pay per click manage’, ‘pay per click managements’, ‘manage pay per click’, ‘managing pay per click’, ‘pay per clik manageers (spelling errors intentional)’.

As you can see, one phrase can quickly evolve to include many variations with this type of matching option.

The advantage of this type of matching option is that you do not have to bid on thousands of misspellings, plural and singular versions, etc.

The disadvantage is less control over your keywords. Sometimes, a word can be spelled correctly, but be considered misspelled. It also does not allow for micro managing very exact keywords based on response rates. (i.e. if the keyword ‘ppc management services’ had a high response rate, and ‘managing ppc services’ had a low response rate, you can not choose to advertise for one and not the other as they are considered variations of each other.

Overture does support a limited amount of negative keywords to help define specific keyword stemming options, and is especially useful for phrase and broad matching.

• Overture Keyword Matching Options: Advanced Match
• Overture Keyword Matching Options: Phrase Match
• Overture Keyword Matching Options: Negative Keyword
• Overture Keyword Matching Options: Standard Match
• Negative & Positive Keywords