When it comes to canonical linking, what you don’t know can hurt your site’s ranking in the search engines. With this in mind, we’ll turn right to the source and rely on advice from the search leader as to how and why attention should be paid to canonical links.
According to Google, a canonical page is the preferred version of a set of pages with highly similar content. Identifying this page is vital for properly crediting the original or main instance of a piece of content. It raises that page in the search rankings against other similar pages, while preserving as much “link juice” as possible. Original content is good, duplicate content is bad.
Studying your server logs or tools such as Google Analytics can help identify pages where similar content is being accessed — even unintentionally.
For example, category prefixes within many Word-Press installations, whether or not these prefixes are actually used or displayed, can provide a hidden source of duplicate content; i.e. a page such as www.domain.com/photos is likely also reachable via a URL such as www.domain.com/category/photos, within a WordPress site.
Another example within the adult arena where specifying a canonical link may be of value is free hosted or affiliate galleries. Consider that a base gallery without reciprocal links would be the preferred page for a search engine to list but there could also be many copies of this galleries — perhaps hundreds or even many thousands of “different” pages, featuring the same content but differing in its reciprocal links and affiliate referral codes. By specifying the canonical link, the cleanest and most profitable gallery should be listed and the other instances of the gallery ignored in the search results.
The easiest way to start using canonical links is by adding a line of code to your page.
?Users can specify a canonical page to search engines by adding a <link> element with the attribute rel=?canonical? to the <head> section of the non-canonical version of the page,? states the Google website. ?Adding this link and attribute lets site owners identify sets of identical content and suggest to Google: ?Of all these pages with identical content, this page is the most useful. Please prioritize it in search results.??
For example, <link rel=?canonical? href=?http://domain.com/galleries/1/index.php?>.
Google recommends using absolute links or specifying a base link so that any relative links will be relative to that base URL. The company also strongly advises webmasters to employ canonical links in cases of minor page differences; and that only one destination URL is used for similar canonical links.
Studying your server logs or tools such as Google Analytics can help identify pages where similar content is being accessed — even unintentionally. By adding canonical links to these pages, you’ll give your main pages a quick boost in the search rankings, delivering more top-quality traffic to your website. Give it a try and see for yourself!