An interesting SEO topic which there’s no hard-and-fast rule about is what to do with outdated material on your website, and if having lots of old content is a good or bad thing for search engine ranking.
The first thing to say is that if there’s nobody looking at a page, nobody ever likely to, and it’s therefore not doing your business any good, then you really ought to get rid of it. The search engines don’t give you any credit for having pages which they have to keep crawling but they never send anybody to.
To summarise, lots of content on a website is good, if it’s relevant and gets visitors. Lots of content which nobody ever looks at does us no good, and may even be slightly detrimental.
For a news website, with the dates clearly shown, the search engines will understand that there’s value in having an archive. But for a business site, the value of old material is far less attractive. Don’t keep it for its own sake.
Of course, as we all know, any pages being retired which do attract visitors (e.g. popular but withdrawn products) should never just be removed. Either ‘301 redirect‘ their URLs to any replacement products, or leave the pages there with a message sending visitors to the new products’ pages.
One company I knew had dozens of case studies from years gone by which it didn’t know what to do with. They’d served their purpose at the time, and most related to long-gone products. Visits to the pages were now down to single figures each year, and the pages had no real search engine presence. The company’s clever solution to the problem of what to do with them was to write a new article ‘looking at some of the many uses its products had been put to over the years’, which was both new, interesting and more substantial than any of the original case studies individually. They published the new ’round-up’ article, set up 301 redirects to it from all the originals, then withdrew the redirects after a few months once the search engines had caught up.
If you have old material with no real equivalent nowadays, and no search engine or other traffic to those pages, you can serve up a ‘410’ code. This tells the search engines that the page has gone, is not coming back, and they don’t have to keep looking for it.