Although Matt filled in for me yesterday to author a quick piece, I thought I'd expand on this topic before flying home to Seattle, as it's raised the ire of several folks hoping for a more thorough explanation. It's also an excellent time to talk about how bad outbound links can affect your website.

At SEOmoz, we've got 10K+ members with profiles, and a visible amount of those were linking to some naughty places (at least, enough to have it mentioned to me in person). Not just spam, but places that none of us who contribute here (or work here) would want to be associated with. The grapevine source basically said - unless you want all links at SEOmoz to lose their value (including those in the blog, on the recommended list, in articles, etc.), you should take care with who you link out to.

The new system will allow folks who contribute to still have those outbound links that pass value (and get lots of clicks - we see the profile page as a whole being on of the most popular pages on the site, so lots of real users are clicking on them). We'll manually approve the folks who get moved into the "contributed a bunch of good stuff" pile so as to prevent linking out to nasty neighborhoods and email you if we have a concern.

This means that a few bad apples won't spoil it for the rest of us. Also - if you've already contributed in the comments quite a bit, we'll be giving credit for those comments in the new system. Matt's working on converting all those comments into points right now.

I'm so sorry that this had to happen, but I also feel that it would have been a bigger loss for SEOmoz to exclude "nofollow" but stop passing any kind of link value. Hopefully, even those folks who disagree with this decision can see my perspective.

So what are the negatives to having bad outbound links on your website:

• You might be perceived as part of a spam/link network and get penalized or banned
• Your outbound links might have their value cut off if you link to too many bad neighborhoods (or even just a few if you're a smaller site)
• Your site's overall authority or quality might be perceived as lower than you'd expect, causing crawling, indexing or ranking to suffer

At SEOmoz, I hoped that we'd never have to worry, because folks who commented wouldn't want to leave links to negative sites (since members would click them to see who was commenting), but that didn't always turn out to be the case. Even sadder is that I suspect (though I haven't crawled through the profile outbounds by hand), that only a few profile creators probably made for most of the problem.

Thanks to everyone for understanding my position - I know it's frustrating, but we'll do the best we can to reward those who contribute and provide value with our links.