Google now says the canonical link element is not recommended for syndicated content; instead, block the syndicated content from being accessed to avoid duplication. Google posted this new piece of information in this help document over here.
What’s new. Google posted this paragraph under the section “syndicated content:”
“The canonical link element is not recommended for those who wish to avoid duplication by syndication partners, because the pages are often very different. The most effective solution is for partners to block indexing of your content. For more, see Avoid article duplication in Google News, which also has advice about blocking syndicated content from Google Search.”
Don’t use canonicals for syndicated content. Previous Google advice was to require those who syndicated your content to use a canonical tag to communicate to Google that the content is being copied from your site. The issue is, it didn’t always stop syndicated content from outranking the original source. Google did suggest you either block or use the canonical tag, Google wrote then “Publishers that allow others to republish content can help ensure that their original versions perform better in Google News by asking those republishing to block or make use of canonical. Google News also encourages those that republish material to consider proactively blocking such content or making use of the canonical, so that we can better identify the original content and credit it appropriately.”
Even before that, Google News had a specific tag to indicate the source of your content. No one used it, so Google stopped supporting it.
Why we care. If you have been syndicated content and using the canonical tag to avoid duplication, it seems Google is now saying that tag won’t do the job. Instead, Google wants you to make sure to block the page from being indexed.
If you have publishers syndicated your content, requiring them to use the canonical tag, is no longer (or never was) an effective strategy to ensure your content would outrank your syndication partners.
Can you force them to block the content from Google? I doubt it.