Showing more Duplicate Title Tags Than WMT

[jamavan]

This is yet another question between moz vs google WebMaster Tools.

In WMT it only shows 5 pages with a total of 18 duplicate titles. But moz is showing 298. It appears the duplicates are canonical links for the most part. What is the discrepancy?

[rjonesx. 0]

That is likely the cause of the discrepancy, although Moz Analytics crawls can be deeper than Google, unearthing more data than Google has gotten to yet.

That being said, I would be hesitant to rely on the canonical tag so much. I did a cursory crawl on your site and found that roughly 20% of the first 800 URLs crawled were duplicates (albeit with the canonical tag). You could potentially eat up your crawl budget from Google if most of the new URLs it is finding are duplicates. While you won't have problems with PageRank dispersion or duplicate content, per se, you will get a shallower crawl of your site. Google isn't going to keep digging if it keeps unearthing the same stuff.

You might want to consider using robots.txt to simply block some of the sections like the /catalog/product/view/ directory if it isn't driving organic traffic and is a source of a good deal of your canonicalized duplicates.

Hope that helps!