Domain Parking: Largely Present, Rarely Considered!

Domain parking typically involves leveraging advertisements to generate revenue on otherwise inactive domain names.
Their content is rarely of real value to users and tends to be
highly similar across parked domains. They have commonalities
beyond content alone: parked domains can share hosting and DNS
infrastructure. Parking rarely receives special treatment in existing
studies (e.g., content analyses or infrastructure concentration
studies). While the presence and possible bias introduced by
parked pages is sometimes acknowledged in studies, the studies still
treat parked domains as any other, either because differentiation
is infeasible, or because doing so is considered out-of-scope.
We argue that the impact of parked domains on analyses
regarding the current state and future development of the Internet
should not be overlooked. In this paper, we motivate this argument
through quantification, and take steps towards helping other
researchers identify parked domains.
We systematically collect a list of 82 parking services and
develop DNS-based indicators to help identify parked domains.
We next quantify the presence of parked domains, using large-scale
DNS data containing hundreds of millions of registered domain
names, representative for a significant part of the global DNS
namespace. Overall, we pinpoint 60 M parked domains, which is a
significant percentage of all names under consideration (23 %) and
identify up to 4 % of domains from top lists to be parked. These
findings demonstrate that the effect of parked pages is potentially
pronounced. We also break down into the various parking services
and DNS zones. This helps us demonstrate and further discuss
the effect that domain parking can have on research and Internet
consolidation