Visitor Segmentation:
- Differentiating of users to site by categories such as age, sex, etc.
 
Being able to segment your visitors helps to target the ads best.  You can look at what pages different segments are spending the most time at and offer up the most relevant ads to that segment on that page.
Having ads more targeted to your audience helps to boost conversion rates. For example, if you see that more women are reading a particular page than men, you can serve ads about clothing, shoes or jewelry instead of ads more commonly associated with men like home improvement stores, sports or video games.
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Glossary Definition From ABC’s of Online Marketing by Alexandra Wharton, Issue 22, Revenue Magazine
				