here is one of easiest way to set up adsense for domains. This method works with all kinds of domain names you use for your sites .But here I have used co.cc domain for example as this method works best on this domain.

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here are steps to setup adsense for domains

1. First log in to your adsense account then click gat ads from adsense set up tab.Click Adsense for domains

2. type a domain name without www. example if you own www.guitarmantra.co.cc type only guitarmantra.co.cc then click add domains button