A Category Filter from a major player such as Google is the first step toward cleaning up the online ad industry as a whole. Granted, it will take a while for Google to refine the filter, for webmasters to become aware of it and for certain webmasters' audiences to pressure them into using it. Still, I think by the end of 2010, ads for dangerous or useless products and services will be the exception rather than the rule, Web-wide.
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