A place called JSTOR (scholarly text archive)... http://www.jstor.org/ allows googlebot to spider their content freely, and this content in turn ranks for the keywords it contains. However, if I click on a result from JSTOR in google results, the resulting JSTOR page tells me that I need to pay a small cost to view the material. It only wants to show the good stuff to googlebot., unless I pay up. Question: Is this cloaking? And: Is it bad?... because JSTOR don't look bad, and they aren't . Will I get my site banned or removed from google if I do this with some of my own content? I want to do this! Maybe JSTOR have a special arrangement with google that allows them to do this? I'm confused!
some webmaster forums are using this technique, They are asking for user registration to view the content for spiders its free. This is similar Cloaking and it may turnout worst if some body report site to google.
It's against google's guidelines to display different content to spiders than to humans maliciously. If it's for genuine aid to spidering the content available it's ok, but if you're showing your users one thing and spiders something completely different (unavaiable to humans) then this is against their guidelines to my knowledge.