When they took over administration of the .CO domain, .CO Internet S.A.S. implemented new domain policies that were more flexible than the historic ones that had been administered by the University of the Andes. The new policies were adjusted to international best practices and defined in consultation with local and international communities. With the new policies, Colombia would be able to sell second-level domain names to the world, such as widgets.co, where previously only third-level domain names were available, such as widgets.com.co.
To celebrate the launch of second-level domains, the registry auctioned the domain name "e.CO" during Internet Week on June 10, 2010. A video of the auction can be seen here:  For a purchase price of $81,000, the winner of the auction was internet entrepreneur Lonnie Borck of B52 Media. Proceeds were donated to a charitable cause of the winner's choice.
As of June 2011, more than 1 million .CO domains had been registered by people in over 200 countries. As of 2013, that number has grown to 1.5 million .CO domains registered worldwide.
More information about .CO and SEO can be found on the Registry's consumer facing website, including videos from Google's SEO expert Matt Cutts confirming Google's positive treatment of .CO for SEO purposes.