If you own domains and you DO NOT have websites developed for those domains, you can use AdSense for Domains. If someone types in the domain name and lands on that page, they will see a page full of ads and no content. If they click an ad you will get paid.
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.