Again, the more quality links a product page has pointing to it directly, the better chance it has of ranking well in search engines. Plus, a diverse link profile (you have some links pointing to deeper pages, not just your home page) makes your site look more authoritative as a whole to search engines.
So when you do acquire these deep links, you want to keep them. But often in ecommerce - product pages come and go. So it's important to make sure your links still give you benefit even when pages disappear.
Problem: 404 Not Found
I recently searched for "top geek gifts" and found Wired Magazine's Ultimate Geek Gift Guide from 2005. It links to 26 products - most are deep pages on the manufacturer or online retailers' sites. Though an old list, it's likely the page still gets a lot of traffic. It certainly ranks well, and the links are valuable to SEO forever.
But only a handful of these product pages still exist, a whopping 13 (that's 50%!) of them are now Not Found pages with no links back into the site, and no suggested alternative products.
Bad for customers, bad for SEO.
Solution? 301 Redirect
Only 20% of the pages preserved the link juice by using a 301 permanent redirect. 3 sites redirected to the home page, while Alienware redirected the page to its Desktop Computer category (one more link for you, Alienware - Merry Christmas) and Sonos to its What to Buy section.
The 301 (permanent) redirect does 2 things - it sends a visitor to a real page on the site, and it tells search engines to pass along any incoming link "juice" (Page Rank) to the page that is redirected to. Whether you redirect to the home page, category page or similar product, the link pointing to your domain helps the overall link popularity of your domain. But redirecting to a category or alternative product page other than the home page is preferable for a few reasons:
- It's more specific for the user. If you redirect the page for a wireless keyboard you no longer carry to all your wireless keyboards, it's more relevant to the visitor than dumping them on the home page.
- It boosts the rankings for the category or page you direct it to.
- It keeps diversity in your link portfolio. Search engines like to see that not all your backlinks point to your home page - looks more natural, and looks like your deeper content is valuable.
You never know when someone will link to you or to what page, so it's best to make this standard procedure for all your pages.