[dns-operations] Peak qps/subscriber rule of thumb for residential ISP networks

[Frank Bulk]

I pretty regularly see stats for peak traffic/subscriber in ISP networks
(currently around 300 to 600 kbps/subscriber for most residential networks
in North America), but I've not seen a rule of thumb for peak qps/subscriber
in residential ISP networks.

What's a typical peak qps/subscriber in a residential ISP network?  We have
6 recursing resolvers in our network (some behind a load-balancer), and if I
add up each of their peak qps and then divide that total by our subscriber
count I get 0.042 qps/subscriber.  I understand that some customer are going
to use Google, OpenDNS, etc, but I assume that other North American networks
are going to see similar substitution rates.  

What are others measuring?

Frank