[cstrat]

is that why that was changed???

[royce]

Yep, that was exactly why (or at least, very strong circumstantial evidence):

https://productforums.google.com/d/msg/websearch/H4XbbwWmtAY...

I don't think it was ever officially announced/admitted anywhere, though. But it was exactly around the time that Google+ was rolled out.

[buboard]

one can say it was used more