Simsi - 3:33 pm on Jul 9, 2011 (gmt 0)
Interesting. I added +1 buttons to each article in the news section of a website a couple of days after this was announced just to experiment.
The news is a service I pay for in a niche industry - very specific but high quality - and comes in batches of 5 - 10 articles every day. I'd guess around 10 sites in my niche use it. I've had the service for 9 months and it gets about 100-150 referrals from Google each day. I am invariably the first to publish each story.
Within a week of after adding +1 buttons, all Google referrals to the news pages has slowed to a trickle (5-10 a day) *. The articles are still indexed but several pages down when they used to always appear in the Top 3 SERPS. It's the only significant change to the site in 3 months (and the only one to the news section in 6 months) although referrals to the other sections of the site are still strong.
Not sure if it's related but the page load thing made me think it was worth sharing. Until now I was thining it was down to a problem with occasional mysql timeouts I have been investigating although I thought that was odd as they are rare (I see them once or twice a week).
It's not the quickest site ("quicker than 54% of sites"), so can/does Google penalise only certain sections of sites based on response times?
* when I say slowed to a trickle, it actually happened suddenly overnight indicating a davluation of the whole section at one moment.