Both the URLs google.com and google.com.cn use a 302 redirect to redirect traffic to Google HK and that’s perfectly fine. The redirected URL doesn’t look clean, not only is it NOT clean, I have a feeling they use URL GET parameters to keep track of some statistics.

Here’s how a sample header looked like:

URL: http://www.google.cn/

GET / HTTP/1.1
Host: www.google.cn
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Cookie: --removed for good--

HTTP/1.1 302 Found
Location: http://www.google.com.hk/url?sa=p&cki=PREF%3DID%3D024bad9e5afabff3:U%3D957ffb38d60fef2f:FF%3D2:LD%3Dzh-CN:TM%3D1269345133:LM%3D1269345324:S%3DokxQi9JZRpNOay9b&q=http://www.google.com.hk/&ust=1269345354859186&usg=AFQjCNGD11Zf8ak_X-V_y6RPXiFMeHqUQg
Cache-Control: private
Content-Type: text/html; charset=UTF-8
Date: Tue, 23 Mar 2010 11:55:24 GMT
Server: gws
Content-Length: 459
X-XSS-Protection: 0

Most of it is pretty boring stuff, but check the Location URL again. I tried hitting the URL a couple of times and it looks like Google is using a very lazy way to keep track of the users redirected from Google china to Google HK.

ust = User Stats?

I looked at the traffic for a few minutes and here are the numbers I got. All of them in pretty sweet increasing order.

1269345163308698
1269345240966267
1269345306123236
1269345354859186
1269345574993411

This could be real or just something I got completely wrong