I agree that this is about controlling traffic rather than organizing data, but to what purpose? It's way too subtle to be a good punishment or teach webmasters a lesson (or we'd have tons more people noticing and talking about it). It doesn't feel like it's something Google is doing
to us - it feels like something Google is doing
for itself that just happens to turn out badly for us.
What purpose it serves, or whether it's a side effect of something else they're doing, I don't know. I can't come up with any reason Google would do this on purpose, so I'm guessing it's a side effect of something else they're doing, and I have no idea what.
All I do know is, my keyphrases shift around, but the amount of traffic they bring from Google doesn't change. I cannot imagine this outcome is worth a dime of effort to Google, and it would take a bit of effort to make this happen. It has to be something that scales, remember? I keep thinking it doesn't matter to Google how many people reach a site as long as they're making money, but then I remembered that whole Net Neutrality controversy in 2010 ([
nytimes.com ]), wherein Google and Verizon were working on a way to "allow Verizon to speed some online content to Internet users more quickly if the content’s creators are willing to pay for the privilege". YouTube gets mentioned as a site that might pay more. I believe this thing never went through, however. Unfortunately, it's hard to track down anything but the initial press releases.
So, I don't know what to think.
ETA: PurpleKitty, you're not alone - that's more or less my story.