jdMorgan - 5:07 pm on Aug 22, 2009 (gmt 0)

It is cloaking in the broadest sense, and many people tend to over-simplify when talking and posting about cloaking on-line. But if it's not an attempt to mislead either the search engines, search engine users, or visitors to your site, then it's not against the search engines' rules as long as you're up-front about requiring a log-in or pay-to-play.

User-agent-based content delivery is very common on sites which serve separate content to mobile devices and desktops -- Sites such as Google, Yahoo, MSN/Bing, Ask, etc. :)

Requiring an account in order to "View the full article" is very common on News sites, although less so now than in the recent past; Users --including me-- tend to get mad if everything I find in the search results leads to sites that require an account (whether free or not) to view anything and tend to go right back to Google and search again or select a different search result. Therefore, this will show up in your pages' bounce rates, which Google tracks.

So be very careful not to put too much content 'behind the wall,' or to try to get too much protected content indexed in search. Bear in mind that if half of your visitors from Google refuse to create an account, then Google will see a 50% bounce rate, and therefore decide that your site must be pretty useless -- even if your content is great and highly-relevant to the search terms used to find your page. If not done very judiciously, requiring an account can have a bad effect on your pages' rankings.

So caution is indicated here, but not because of the user-agent-based content delivery (cloaking) per-se.

Jim