Occasionally, an update is totally pointless. You need to delete the post or the article and just get rid of it! If you're an online entrepreneur, this is a project you should do in your “down time”, i.e. after you've taken care of your priority tasks: banging out blog posts (or articles), responding to comments, social media sharing and other blog promotion activities, etc. Perhaps set aside a few hours each week or every other week to revisit and review old blog posts.
If you have affiliate marketing websites or blogs, sometimes vendors you are approved for discontinue their program. You don't always get the memo or the eMail. You should test your referral links at your site to make sure they lead the visitor to correct landing page. Often my click testing indicated the link is inactive which is not only upsetting because there was no notification as to “when” that happened, but it also makes you wonder how many other people also clicked it, got the error message, and then left your site never to return. (My thoughts or worries.)
There are supposedly free tools that can help you with this effort, i.e. help you find broken links. They are available but I have yet to use one successfully. However, others have. So don't let my lack of skills hinder you.
It's your work and if it's perfectly good work, don't let it go to waste. This blogging tip can not be stressed enough. If you serious about your blogging, then make time to refresh or update your old content. Content that dates back several years may still be critical and relevant. Do your best to salvage what you can. You never know. May be a gold mine buried in there!
Don't just take my advice. Listen to the advice of professionals.
