Google has introduced two new link elements to show Google the schematic relationships of documents that span multiple pages and better identify duplicate content. Google also emphasized they want to show single-page versions in search results.
Pagination & SEO
Simply, pagination is the sequential numbering of pages. In reference to the web, pagination means dividing a document, file, or database entries into sequential parts.
Many common blogs and CMS and forum platforms utilize pagination. In fact, it’s possible pagination is happening on your site without you even realizing it. Pagination is used in traditional publications, word processors, by search engines (see the bottom of Google's results pages), and even Gmail.
For example, a long article may split into three pages, with links to “next” and page two and three at the bottom of an article. Or a typical blog might show 10 blog posts per page, with options at the bottom to go to “older” or “newer” posts.
Previously, there has been no set standard for usability of multi-part pages when doing SEO. For quite some time most webmasters have searched for ways to better optimize utilizing pagination.
Introducing rel="next" and rel="prev"
In the past, the pagination solution was to add unique titles and descriptions for every page. Now, you can also show Google how to process your paginated resource with the use of rel="next" and rel="prev".
Adding rel="next" and rel="prev" is fairly simple, identifying where pagination is happening on your site is the first logical step. Next, determine if there is a “View All” page and if it’s currently being used properly. If not, and it is easy to implement tags, so be it.
The rel="next" and rel="prev" tags are useful for highlighting relationships on a series of related articles, product categories, multi-part forum threads, or comment pages.
For those of you who dislike abbreviations, feel free to use rel="previous" as a syntactic variant.
View-All Pages and rel="canonical"
Our old friend rel="canonical" is back, and it has found a new purpose. What was touted as the meta tag to identify the original source eliminating duplicate content, should now be used for a “view-all” page containing the entire paginated series.
In a separate blog post, Google stated on the they would prefer returning the “view-all” page in the index, rather than displaying each page. This way they don’t have to “guess” which page to rank for the entire document title. The view-all page is a much more accurate way to gauge relevancy and accuracy against the search query.
A “View All” page is recommended, except if the load times are too high or has poor navigation. If that is the case for your site, use the rel="next" and rel="previous" tags instead.
The rel= tags are certainly adding up from Google. To me, there are simply two frames of thought.
The first is: Google should be doing this internally. Isn't it their duty to keep their search engine indexing and ranking the right pages?
The second: keep it coming Google! This is job security, period!
Personally, I'm somewhere in the middle.