That patent didn't describe throttling, it described measuring impressions by domain as part of another process - and it mentioned it as a side point, no as the key focus for the patent. I didn't have the time to dig it up right now, but it goes back at least 3-4 years, I'd say.
no throttling mechanism per se, only the temporary appearance of such
By "temporary" you'd have to mean months to account for some of the observations - even the same Google search traffic levels on weekends and weekdays. Or no traffic at all after 1 pm, day after day - even though there are 100s of visits per hour until 1 pm.
And what about drall's recent post above, where a traffic spike for one keyword is balanced out by lost ranking positions on other words until the spike goes away?
I don't say traffic throttling is common, but I do say it exists in some cases. I've seen too much to think the idea is all tinfoil hat - that's why I resurrected the topic. And drall is the first person I know of who has pinned down the "how" of it.
As in the past threads, it is easy to doubt that traffic throttling exists. I've been back and forth on it myself, because it IS a very strange idea - and after all, who would want it to be true?
But the French Academy of Science once said that hot stones don't fall out of the sky, too. Just because almost no one gets to see a meteorite fall doesn't mean they don't exist.