Hi, I've seen websites implement nofollow links. Why do websites do that? What happens if the owner of a website uses nofollow links for all external content. Suppose you want to credit the author of <INSERT SOMETHING HERE> and you backlink to his/her website. Is it wise to use a nofollow link? Regards, FY
Most bloggers implement it to avoid comment spamming, same goes for forums and every kind of site that interacts with the user. The benefit may be that your web site doesn't look like a link farm (crappy sites with the sole purpose of creating backlinks).
If you want to credit someone, and you trust their website, don't use nofollow. The purpose of nofollow is to tell Google that this link is not a "vote" in favor of the site from you.