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-- Pay Per Click Engines
---- Click Fraud Rate Up to 17.1pct in Q4 2008
Nuttakorn - 12:08 pm on Jan 29, 2009 (gmt 0)Thread source:: http://www.webmasterworld.com/ppc/3836761.htm
I also see some invalid clicks appear in Google adwords after using PPC Audit, it quite lot of expense especially expensive keywords.
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