Many eCommerce sites will have products that they will stop selling as new products become available. This can pose an issue for your seo and your users.
Leaving pages live for products no longer on sale can be frustrating for visitors looking to buy them. They visit your site looking to purchase, only to realise once they land on your product page that the item has been discontinued. This can increase bounce rates which may have a negative effect on your search rankings.
You could also remove the pages, but if people are looking for information on those products, they may find it annoying that it is no longer available. Simply deleting the pages would also waste any value gained from links to those product pages.
Matt Cutts added a new video to the Google Webmasters channel on YouTube, answering how eCommerce sites should deal with product pages for discontinued items. He provides three scenarios and the best ways to deal with them, both for search engines and users.
Small eCommerce sites
For small eCommerce sites that sell unique items, they could consider doing a custom 404 page that mentions other related products. This is beneficial since users will be made aware that the product they searched for is no longer available. Search engines will see the 404 status code, eventually removing the page from the search results. In addition, any inbound links to the page won’t be entirely wasted as the value will be able to pass through any internal links on the custom 404 page.
Medium sized eCommerce sites
Matt states that for medium sized eCommerce sites, pages for products that are no longer available should just be 404’d. He makes a good point that “You don’t want to known as the product site that whenever you visit it, it’s like ‘Oh yeah, you can’t buy this anymore’”.
Large eCommerce sites
For large eCommerce sites, Matt suggests the use of the META tag ‘unavailable_after’. This effectively tells Google to not crawl a page after a specified date. This will eventually result in the removal of this page from search results.
Strangely, one thing Matt didn’t mention was using 301 redirects for discontinued products. This may be because it could be confusing for visitors. For example, Bob thinks he will land on a product page about blue widgets, but ends up on the red widgets page. Using 301 redirects may not be terrible for a user’s experience so long as the product being redirected to is very similar to the discontinued product. It may be worth testing conversions using a number of the above methods to see which works best for your visitors.