The Inside Adsense Blog has just announced that Adsense for Domains is now available to all publishers who owns several domains which are not really live sites. Whereas previously the only way that domain owners can earn from their registered dormant sites was to let third-party publishers to run their ads on those and then earn a miniscule of earnings. But with the Adsense for Domains open to all publishers, everyone can now run Adsense on their dormant domains regardless of whether they own only one or two domains.
By being available to “all publishers”, Google meant only those who are located in the U.S. Google Adsense is yet to roll this out to “all publishers” worldwide.
Although this would not make domain owners ultra-rich with revenues, it is however a better deal than letting other advertisers not connected with Adsense run their ads on those domains. If you opt to join Adsense for Domains, which you can do so by visiting your Adsense account, Google will run ads, links and search results on the dormant domains and will add more useful information in the near future.
Instead of paying them for nothing and hoping someday that somebody would buy it a high price, might as well run Adsense for Domain there.