Wordpress: When default SEO goes very wrong
I just recently stumbled over a problem with Wordpress that I never gave any attention before. Most likely because I generally don't give Wordpress much attention. Wordpress comes with an astounding bad SEO optimization out of the box.
When you have a standard Wordpress running (as in no modules mangling with SEO) you'll end up with blog posts containing prev and next rel links mirroring your prev and next navigation on that page. On first sight this might seem like a logical thing to do. You have it for your users. Why not have it for search engines as well?
The problem here is that these links are not supposed to point to a random unrelated entry but to one in a set. Most posts on blogs are not related to each other. They are just the next or the previous entry of some other entry. A navigation's purpose is not to go to the next page but to make reading entries more fluid. The links however are specifically for the other option.
They are most important for paginated content where one article is split into 2 or more pages. They can be useful in categories. Generally however they are not unless a category is closely related to paginated content. I.e. if users are supposed to read more than just one single post.
So why is it bad for SEO?
The way Google understands these links is the paginated article version. And in that context it makes a whole of a lot of sense to emphasize the first page in the set. This also means the rest of the pages become less relevant as they are a sub-element of that indexed first page. If you have paginated content this behavior is favorable. If you however do not and implement this feature on actually unrelated content it will weaken said content.
From Google's POV the blog of a standard Wordpress installation looks like a huge fucking article spreading over dozens, hundreds or thousands of pages. And the first one will be the 'entry page' for that article. It obviously does not mean Google is not going to index them. It will. But using next and previous rel-links weakens them for no other reason than misunderstood usage of the element.
If SEO is important to you, you probably run an SEO plugin and most of them fix that issue. If you think Wordpress does a good enough job for you ... well. In this case it absolutely does not.