I have a product on my eCommerce site that has three separate pages. They are quite similar except the title denotes different sizes. A quick check shows me two of the three pages show up in the top 15 (8 and 15) for the pertinent keyword. Would there be any benefit to adding canonical tags to the two lowest ranking pages that point to the best ranking one? I'm wondering if doing this might help me get in the top five or better. Thanks for any tips.