Matthew Mullenweg, of WordPress fame, has posted the wistful thought that adding NoFollow tag support to WordPress didn’t really help with the problem of web spam. I emphatically disagree. Yes, it’s true that comment spam and the like is still a huge problem.* But while crude spam isn’t visibly affected, the NoFollow tag probably does a great deal to discourage something that would be even worse.
*Uh, Matt, can you do anything about increasing the 150 capacity limit of the Akismet spam quarantine? I run over it all the time, often in less than 24 hours.
Suppose it were still the case that spammers could get search engine ranking boosts from blog comment spam. Don’t you think they would be motivated to craft subject-specific comments that are very hard to distinguish from the real things? Search engine ranking algorithms are taking ever more accounting of the topics of pages that link to sites, the topics of the pages that link to THOSE pages, the topic of the text around the link, and so on. Few forms of search engine optimization are more valuable than “good” links. A comment that stayed up on a popular and topic-relevant blog would be of high SEO value — think $25-$250 in perceived value as a super-rough estimate — and great efforts would be devoted to getting them. The whole blogosphere might be corrupted in the process.
Blog software’s adoption of the NoFollow tag is a VERY good thing.