Performance & Scalability benchmarks from the household names

Hi,
I am looking for performance & scalability statistics regarding the household names.

For example how many pages, transactions, concurrent users etc the household names such as linkedin, facebook, twitter are able to do per second?

Many thanks

Like you, I remain interested in this too, but so far I haven't come across a page where all of them are listed in one place. So I follow High scalability portal, and dev talk presentations on Slideshare and InfoQ to get some hints. Use their search facilities to search for architecture presentations by their developers, and derive numbers from them. Some other useful resources below:

Facebook:
- This page helps - http://www.facebook.com/press/info.php?statistics to derive metrics like number of transactions per second.

Twitter:
- http://blog.twitter.com/2011/03/numbers.html
- ~1700 tweets per second [Apr 2011 estimate – from a tweet by @kevinweil that twitter is doing well over 150million tweets per day]

Wikipedia:
- http://en.wikipedia.org/wiki/Special:Statistics
- http://stats.wikimedia.org/EN/Sitemap.htm

Google search:
-34,000 queries per second [Feb 2010 estimate] (2 million per minute; 121 million per hour; 3 billion per day; 88 billion per month)

Linkedin:
- No idea about recent numbers. But they crossed 100 million registered users couple of months ago. Here's an old link - http://hurvitz.org/blog/2008/06/linkedin-architecture

Also have a look at http://highscalability.com/