High-value Internet domain names can sell for hundreds of thousands of dollars, while domains of lesser value are abandoned by their owners and become available for re-registration. Yet, there appears to be enough residual value and demand from domain speculators to give rise to a highly competitive ecosystem of drop-catch services that race to be the first to re-register potentially desirable domain names in the very instant the old registration is deleted. To pre-empt the competitive (and uncertain) race to re-registration, some registrars sell their own customers’ expired domains pre-release, that is, even before the names are returned to general availability. These practices are not without controversy, and can have serious security consequences.

In this paper, we present an empirical analysis of these two kinds of post-expiration domain ownership changes, and we characterise the competitive ecosystem from a technical point of view. We find that 10% of all com domains are re-registered on the same day as their old registration is deleted. In the case of .org, more than 50% of re-registrations on the deletion day occur during only 30s. These findings highlight a significant demand for expired domains, and hint at highly competitive re-registrations. Our work raises the question whether the current situation of post-expiration domain ownership changes is open and fair to all interested parties.