backdraft7 - 6:57 am on Sep 10, 2012 (gmt 0)
@tedster - when traffic levels remain steady and serps are pretty much unchanged, yet traffic quality suddenly switches from "good" to "bad", what can you check? It's all US traffic, not suddenly foreign. The only thing I can see that is changing is the bounce rate, which went from about 42% to 57%. Why? Only Google knows.
I know sales conversion rate probably doesn't help, but when it was like clockwork on the same traffic levels between the years of 1999 and 2010, then slowly evolved into the ON / OFF periods we regularly see today, it just confirms some sort of manipulation. How or why they are doing it is a mystery.