On: Reducing website spam

[rplnt]

As outlined in another comment, marketing/seo is often the reason. That is, bots will spam links. Either they want direct clicks or at least some SEO bonus.

[eli → rplnt]

The worst is the bots that are smart enough to figure out how to post spam on your site, but not smart enough to see that it's all rel=nofollow

[TomGullen → eli]

Working out if they are nofollowed or not probably is comparable effort to just posting the spam link! Therefore just posting the spam link is probably the best strategy for them.

[Natsu → TomGullen]

For one link, yes, but for the entire site? I wonder.

I can't imagine there are any search engines important enough to optimize for that don't use the rel=nofollow cue.

[danneu → eli]

I'm not convinced nofollow links are valueless.

[danneu → danneu]

Source: http://www.socialseo.com/blog/an-experiment-nofollow-links-d...

Google "nofollow seo value" to find other insights.