Can I specify the canonical of all of a product’s review pages as a single URL?

Matt's answer:

Today’s question comes from Steve in Salt Lake City, Utah. Steve wants to know yea or nay, putting a canonical tag on individual product review pages that each points to the “all reviews for this product” page for this particular product, assuming we’re really not that keen on the individual review pages ranking. So if I understand what you’re saying, imagine that you have a product page for a red widget or something like that. And you’re saying you have individual pages for small little snippets of reviews. And rather than having those four or five little small snippet pages of one page for one review, another page for another short review, rather than having each of those individual pages ranking, you want to put a canonical tag on those to point to the overall product page or the overall product review page. That’s a perfectly reasonable way to use the rel=canonical tag. Now you probably shouldn’t do something that is vastly, vastly different, like rel=canonical a red widget to women shoes or something like that that’s completely unrelated. But something like individual product review pages or individual URLs to sort of a global or master page for that particular product. That’s a perfectly reasonable way to use rel canonical. Now, be thinking about it in that it might turn out that those individual pages would convert well, so you want to do some testing. You don’t want to just blindly say I think this is the best way to do it and so I’m just going to plunge straight ahead. Look into the conversion rates and all that sort of stuff. But if you reasonably conclude that yeah, you’d rather have those pages all glommed together into one, that is something that you can do with rel=canonical.

by Matt Cutts - Google's Head of Search Quality Team

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