Should I Block Tag, Category, Author Pages

[Falconberg]

Just finished reviewing the first crawl of my first SEOmoz campaign for a site that I am working on.  The site I"m working on uses Wordpress as a CMS, and most if not all of the warnings and notices have to do with author, category, and tag pages. Should I block these from being indexed? Why or why not?

[EGOL]

I have my blog set up so that I can easily get traffic data and revenue on categories, recent posts, and permalink pages.

All decisions on what to index, what to promote and where to place my effort are based upon that data.

[Falconberg]

Thanks for the quick response. These pages aren't generating traffic, and I am not even sure that they are indexed by Google.  Most of the posts, patricularly the newer ones, use the canonical rel tag. Would there be any downside to blocking these pages?

[EGOL]

It is possible that the same content is appearing at several locations on your site.  That can lead to duplicate content problems or some of your linkjuice being wasted in the promotion of very similar pages.  For example your category pages and tag pages might be almost identical.

If you have a very strong site you might get away with it.... or if you have a blog that gets a few posts per day the constant shuffle of content might be fast enough that google will not realize the amount of duplicate items that you have.

I would run analytics on the pages and see where the traffic is being pulled in before I make a decision.  It is possible that some of your pages pull very little search traffic and there will be very little loss from blocking them from being indexed or cutting off links to them.