About a decade ago Opera Mini did 150k transcoded full pageloads/s (times about 30 inlines per pageload that was the average back then, so about 4.5 million requested/loaded/processed/compressed HTTP resources/s).
(All of the public Google Search numbers I've seen have seemed one or two orders of magnitudes too small. Or maybe most people don't use their search engine/browser as much as I do, so my perspective is skewed...)
From my experience with that scale of traffic (with Opera Mini at the time about 250M MAUs and 150k full pageloads/s):
There is surprisingly little seasonal variance. You have your weekly/daily traffic rhythms based on when your users are awake/active based on their geographical distribution and that's mostly it.
"World events" also have very little impact - they tend to barely make a dent in that massive background noise.
Before we had large volumes of traffic I thought we'd be seeing all sorts of unusual peaks, after a few years I realized growth at scale tends to become boring (but in a good way).
