I just test by do google search for many keywords. I use Google.com and inserted parameter &gl=us to make global setting as USA. I found some keywords result show different between "us" and "US". You may try it yourself with your own keyword by copy below code and paste to your browser http://www.google.com/search?q=keyword&gl=US Code (markup): replace "keyword" with your keyword and try to switch between "US" and "us" and you will see some keyword show different results, not all keywords. This is also work with other country extension such as uk/UK, ca/CA too Just try it
I think google search in case sensitive (some case) they think us means ours and US means United States
I don't think Google would define different between capital alphabets and non-capital one in "global" field value That would messed up. As I stated, not all keywords being shown differently, just some keywords.
This is interesting. I can't really speculate why it should show different results. Maybe each permutation (us, uS, Us, US) is sent to a different datacenter?
There have been a number of reports noticing the case sensitive results in Google SERPs as early as 2/21 in the UK. Google clearly states in The Essentials of Google Search that "Google searches are NOT case sensitive".
That's very interesting! It's contradictory to most of what I've read. According to google's official help center, google doesn't recognize capital letters. "Google searches are NOT case sensitive. All letters, regardless of how you type them, will be understood as lower case. For example, searches for george washington, George Washington, and gEoRgE wAsHiNgToN will all return the same results." http://www.google.com/support/bin/static.py?page=searchguides.html&ctx=basics&hl=en