> I don't understand what users have to do in this context. It's the queries > that affect DNS servers.
It's obviously true that the number of queries is the cause for introducing any limitation/pricing scheme. But it's pretty hard for a receiving site to actually know how many DNS queries they're doing towards a particular nameserver or a particular zone (it would require extensive logging and log-parsing). Number of users or number of messages is a good approximation of the number of actual DNS queries, and sufficiently simple to determine. At dnswl.org, we consider any source (being losely defined as a /24 doing more than 100'000 queries / 24 hours as a "large" user, and ask them to switch to rsync access (however this is not strongly enforced at present, and does not involve money). -- Matthias
