The fact that CEOs.mobi wasn't among the first ones to get a bid suggests that some development ideas may not be as readily apparent at first glance as I thought.
How about a listing of the office phone numbers (direct lines, switchboard and/or cell phone where appropriate) of the CEOs of all companies in the known universe (as an aspiration of course)?
You can do that in many different ways - for instance starting with a free database of Big Business' public domain info (which would cover say 20% of the data volume but 80% of all searches for similar info on the internet), and then - once you get a good idea of the steepness of the usage curve - just get the best among the numerous providers of directory listings (Microsoft just bought one, but there are plenty left) to compete for the privilege of licensing their content on CEOs.mobi
????: NamePros.com http://www.namepros.com/mobi-marketplace/300912-hundreds-lll-mobi-prime-dictionary-terms.html
Marketing should be relatively easy, especially if you explore the less obvious angles - like letting users market it for you instead - telling their friends about this great new service that lets you yell at a CEO
(or at least their secretary) in seconds - rather than at a hapless Customer Support person and begging to be put through to a supervisor
...