I have a private forum site that requires registration for viewing. I want all threads to be indexed by search engines but when human user click on search engine listings they will get redirected to registration page before they can view the thread. Will this be harmful to my forum site in term of SEO? Thx!
Depends how you do it. There's a wrong way of doing it; cloaking. That will get your entire forum wiped. Do it like Webmaster World does and you'll be fine.
Very true TOPS3O, clocking will get you in deep sh#*t. So, dont ever do clocking. You can do it by some other way, which is Google friendly.
A lot of the larger sites cloak for google and other search engines with no problems at all. It depends how you do it. http://www.seomoz.org/blogdetail.php?ID=1251 http://www.seroundtable.com/archives/003962.html
Cloking would be to supply a deviant page to Google's search bot. What you really would be doing is supplying the actual page to Google. What I think WMW does is shows the actual page if the GoogleBot is the one visiting. If it is not then you do a temporary redirect to your login page. Also WMW has a robots.txt file that tells Google not to cache the pages. If Google cached them, then you could just view their pages. I hate WMW btw.