Missing Category Canonical Links
So this site is built with Magento, and one of the bad things about Magento is that without any SEO extensions it doesn't create canonical links for categories or products.
A canonical is essential to stop Google indexing duplicate urls of the same page, which can occur in many situations such as when a product is visited by more than one category url.
And this leads onto the next problem with duplicate content.
Massive Amounts of Duplicate Content Indexed
The lack of canonicals has led to every single category page filter being indexed as a unique url in Google.
This is a big problem, because it can cause your website to be penalised by the Panda algorithm. It can also result in the wrong variation of url being ranked in Google search which creates keyword cannibalisation.
How to fix this problem?
The correct way to fix this is to use canonical urls, which will self reference to the category url and prevent the filters being indexed.
If it is a very large site then you can prevent Google from wasting crawl budget on these filter urls by adding the nofollow attribute to the internal links of the filter, or alternatively by blocking the rules in the Robots.txt file.
302 Redirect for HTTPS Implementation
I have seen this so many times and yet didn't realise it was such an easy mistake to make. Their HTTP version of the url is redirecting to the HTTPS version, but it's doing so using a 302 redirect.
The 302 redirect tells Google this is a temporary redirect, and also negatively impacts the link equity passed through it, which could mean they are receiving a fraction of the power they once did for their inbound links.
To fix this, they should swap it to a 301 redirect.
Un-optimised News Category Pages
They produce some great informational content on their blog, and most of their high traffic pages are actually news articles, but they haven't optimised the meta information for their News category pages.
A good example of this is for the keyword "bouldering videos" which they rank on page 2 for, but actually have some of the best content in the space on. By simply optimising the title and meta description of their bouldering videos category they could move up to the first page for this keyword.
Broken Backlinks
They have 3,747 backlinks going to 404 pages, which means they are wasting a lot of their inbound link equity. To fix this, they should 301 redirect these urls to relevant pages on the website.
Summary
There are some fairly big errors here, that once fixed could improve the search traffic of this website immensely.
If you have similar problems with your Magento ecommerce website, then I can help you fix them, simply contact me about consultancy options.
