A decline in an existing resource’s performance over time, which requires investigation to understand its causes.
Content decay is a term used for declining performance of an existing resource over time. A page might lose search clicks, visibility or another chosen outcome. The observation is a reason to investigate, not a diagnosis that the writing has become outdated.
Possible explanations include changes in demand, search results, technical access, competition or the page itself. Reporting changes can also affect what the numbers show. Compare appropriate periods and check which queries or audiences changed before assigning the decline to one cause.
An update should address an identified problem. Correct stale information when it exists, improve an unclear answer or repair a technical issue as appropriate. Changing the date or adding paragraphs without evidence may leave the actual cause untouched. Some pages remain useful even when their search traffic is lower.
Takeaway: Use declining performance to trigger a focused review. Separate content problems from demand, measurement and technical issues before choosing a repair.
Example
A wedding supplier’s guide receives fewer clicks after its main booking season. Comparing that decline with the equivalent period last year may reveal a recurring pattern rather than an outdated guide. If the page also lists discontinued packages, that factual problem still deserves correction independently of the traffic pattern.
What to check
Define the metric, date range and affected pages before investigating. Keep a change log and check useful business outcomes alongside traffic. Avoid deleting a working customer resource merely because its peak search performance has passed.
For more detail, see Debugging drops in Google Search traffic.