netmeg - 7:57 pm on Mar 3, 2013 (gmt 0)
They have enough ad inventory to run on their publisher network. They may not have enough relevant inventory to run on some individual sites.
I don't know anyone (other than maybe the Black Friday people) who have spikier traffic than I do - on one site I can go from a thousand pageviews a day to well over a million a day - and believe me, my revenue changes accordingly.
But - if you want to believe you're being throttled, then believe it.