I was surprised to learn recently that many people recommend using the noindex meta tag on tag pages like this one: https://xfrocks.com/tags/widget+framework/
It surprised me because one of the reasons that I think tags are so important is that I have been amazed by the SEO performance of a WordPress site I manage. The best explanation I could find was the extensive tagging built into WordPress. I think of WP essentially having four tagging systems built in: "tag," category, date, and author, and this must provide terrific anchor text and internal linking.
However, some people seem to believe that tag pages should be marked "noindex." The best source is a study published in Search Engine Journal in 2012, where they saw a 20%+ increase in organic traffic after setting tag pages to noindex and also optimizing post pagination. A blogger reported a 300% increase in traffic from noindexing the tags page. A Moz article on setting Wordpress up for SEO success also recommended it. Several forum threads also discuss it: MozQ&A1, MozQ&A2, StackExchangeWebmaster.
I'd be curious to hear what others think of this. Because XenTag doesn't use snippets, it may avoid a duplicate content problem that WordPress has with tag pages. (Most of the best practices posts about tagging focus on WordPress.) However, if duplicate content problems were the issue with WordPress, why aren't people advocating decreasing the size of the snippets rather than using noindex?
I'm a big fan of Xentag. I wonder if it would be hard to add a "noindexed tag pages" option to XenTag. Setting aside all other concerns, it is easy to argue that tag pages make bad landing pages for organic searches, so admins might want to noindex them anyway.
Interested to hear people's thoughts...