To nofollow or not to nofollow

What's the general consensus on adding "nofollow" to all external links? Is it best to have it on or off?

I have no Viagra spam or anything like that on my forums, so I'm tempted to pass along my PR.

Thoughts?

i have everything nofollowed exept for what i manually white-list (mostly, my other sites).

it's not about passing PR.... it's about keeping the spiders who come to my site on my site

Not all bots treat it as literally a nofollow though (source), but it is a good point and one I think I'll follow. Thanks.

We follow a different approach here we allow all the links except a bunch of blacklisted sites with nofollow

Would like to have opinions please

we promote online gambling sites and so we have many affiliate tags
Should i use the rel nofollow for external links or better not?

Is it true that google gives penalties if you add nofollow to all outgoing links?

Please let me know what you think

Thanks
Marina

Adding a nofollow doesnt prevent spiders to leave your site. They really follow a no-followed link. Only the no-follow prevents PR to be passed.

Adding a no-follow to an external link that is related to the topic in your forum is not a good thing to do. Google appreciates relevant external links to quality content. So IMO adding a nofollow to all external links is not a very good idea. Better monitor all the postings and edit them in case a lousy external link was posted.

I understand that point
thanks so much for explaining this to me ekantnl
I will remove the no follow now

After reading this post, I have disabled the nofollow tag on all external links and added a blacklist!

Thank you!

Is the general consensus, then, that we should not be nofollowing all external links? Can it have adverse effects?

I would like to be able to add nofollow to specific forums only. Like the off topic forum we have. Some really goofy links in there that have zero relevance to our site.

Want to continue this discussion.
Do follow or not to follow, this is the question

Although, I don't have any PR on my thread-pages ... so I don't have PR to pass, do I?

I don't see any use in adding nofollow to external sites, either...