If you search for [tweetdeck] in Google TweetDeck.com doesn't show up. If you do the same search in Bing for [tweetdeck], TweetDeck.com does show up. If you go as a user to TweetDeck.com, the page does render.
So why is it not showing up in Google? That was a question asked in Google+. The answer is not that obvious, and it took a Googler to do some investigation work to find out why.
Google's John Mueller noticed that when the useragent GoogleBot accesses TweetDeck.com, it is requested to 301 redirect to Twitter.com. In short, it is only redirecting GoogleBot from TweetDeck.com to Twitter.
John explained:
It looks like they're doing this based on the user-agent. Checking with Googlebot shows the redirect:$ curl -s -I -A Googlebot http://tweetdeck.com/ | grep -E "(HTTP|Location)"
HTTP/1.1 301 Moved Permanently
Location: http://twitter.com/Using "Bingbot" shows a 200 OK:
$ curl -s -I -A Bingbot http://tweetdeck.com/ | grep -E "(HTTP|Location)"
HTTP/1.1 200 OKUsing "Slurp" shows the redirect again:
$ curl -s -I -A Slurp http://tweetdeck.com/ | grep -E "(HTTP|Location)"
HTTP/1.1 301 Moved Permanently
Location: http://twitter.com/Theoretically there's also a chance that more is happening on an IP level, or that a very specific user-agent is being looked for, but if it's reacting based on a simplified user-agent like this, then I imagine that's what it's set up for.
Is this really cloaking? You can learn more about Google's definition and views on cloaking over here.
That being said, two questions:
(1) Why is Twitter doing this?
(2) Will Google take action against this move?
Forum discussion at Google+.
