As your older blog posts accumulate links, shares and social media traffic, they’ll grow in visibility and traffic. With that in mind, it makes sense to periodically re-evaluate your older posts, and optimise them for maximum conversions.
The more congruent your offer is with your content, the better your conversion rate will be. If you’ve written a new whitepaper, or created a new resource, link it to existing relevant posts. When HubSpot did this, they doubled the lead generation of their old posts.