Quality score remains one of the more ambiguous ideas on the web. Google has become much more transparent with sharing information about AdWords quality score.

Microsoft adCenter has also announced it will use a quality score formula to determine placement. I’ve had some discussions with Microsoft digging into the full algo, however, here are some high level facts that will help you optimize for adCenter’s quality score.

• How closely related the keyword is to the ad’s content (single factor)
• How closely related the query is to the landing page (single factor)
• How closely related the keyword is to both the ad and landing page (combined factor)
• The serial chain of query to ad and then ad to landing page
• Uniqueness of the ad to other ads on the page. adCenter tries not to show duplicate ads on the page (this is an interesting one).

Overall, it’s fairly similar to Google’s.

The concept is quite simple: If you are enhancing the search process, then ads rank well. If you aren’t, then ads rank lower.