Content decay
The slow traffic slide of a page that once ranked, because it aged while the query and the competition moved on.
See it
What it is
Not a penalty, just entropy. A guide that ranked two years ago drifts: screenshots show an old UI, prices and version numbers are wrong, half the outbound links are dead, and three newer pages answer the query better. Traffic slides a few percent a month until one day the page is on line two.
The graph shape is the diagnosis. A gentle multi-month decline on a specific set of URLs is decay. A cliff across the whole site on one date is an algorithm update or something technically broken. Decay also runs at different speeds by query: 'best CRM 2026' rots within months, 'what is kerning' barely moves in years.
The routine: quarterly, sort pages by loss against their own peak, take the top ten, and refresh them properly. Refresh means fixing what became false, adding what the current top results cover and you do not, replacing dated examples, and re-checking intent, because the format that ranks now may have changed from an essay to a comparison table. Republish on the same URL, keep the H1 and slug. Gotchas: changing the date without changing the content works once and then stops working. And a page that never ranked is not decaying, it is just bad; decay only applies to pages with something to lose.
Ask AI for it
Refresh this page for content decay without changing its URL, H1, or core angle. Go through it and mark every fact that has expired: prices, version numbers, dates, product names, screenshots, dead links, and 'currently' claims. Rewrite those sections with current information. Then compare against what the top-ranking pages for this query now cover and add the two or three sections we are missing, in our voice. Finally, tell me whether the ranking format has shifted (guide versus comparison table versus tool) and what restructuring that implies.