There was a time when I used to face this problem on regular basis as I had lots of clients all from the eCommerce sites.

This usually happens when your internal linking strategy is not satisfactory. The idea is to reconsider your internal linking strategy and fix the problems and you will see categories will started rank for their key phrases.

Hope this helps!

If you compare 404pages with 301redirections I believe 301 is a better option and here is why!

When a visitor of your website reach to a page that is no more present on your website, they will find the 404 page which may leads the visitor to bounce from the website as usually 404 pages hurt user experience.

The idea is to 301 them to appropriate pages so that they never see any broken page on the website and can easily perform the desired actions while continuing their journey on the website.

This will also help increasing the time on site which will impact positively on your site nad rankings in search engines.

That’s great that you can get a link from Gov website but the link will be in the footer and this means every page of the website will be linking back to you as normally websites share the same footer across the website.

Google like natural links and when you will use a key phrase to link back to your client’s website (especially in the footer) this will hurt you as Google can easily guess that the link has been created to manipulate SERP results.

My opinion, if you are linking from footer is to get link on brand name instead of a keyword this way you will get the link juice. I am not saying you will be able to achieve your goal but still you will increase the website authority which will help you in different ways.

You also said that you don’t have lot of unique content for each page. There is no shortcut or pass here you have to create unique content for pages in order to increase your chances to rank for different county related keyphrases.

Honestly, this strategy in my opinion is not good and Google can easily guess what you are doing and reward you accordingly.

I think the better idea is to get a link with a brand name to increase authority, create unique content for county pages. Get some quality links from different industry related websites and you will rank better in SERPs from the targeted key phrases.

Just a thought!

I agree with Peter, I have worked with a company who had several different products that are huge so they used the similar structure. I think in order to give better user experience they should have some text on home page (instead of image only) but i think from the technical SEO perspective there is no big problem with this!

Ok, this is how I look at the situation.

1. ABC.com
2. ABC.com/index.php

So you have two URLs and the question is either to redirect301 or use canonical? In my opinion 301 is a better solution and this is because it will not only redirect people to the preferred version but the link value as well.

Whereas, with canonicals only search engines will know what is the preferred page but it will not transfer the link value which can help you with organic rankings.

Hope this helps!

I believe when you are talking about 1 to 5 million URLs it is going to take time no matter what tool you use but if you ask me screaming frog is a better tool and if you have a paid version of it you still can crawl websites with few million URLs in it.

Xenu is not a bad choice either but it’s kind of confusing and there is a possibility that it can broke.

Hope this helps!