Content decay is the slow loss of organic traffic to a post that once performed. It is predictable enough to plan around, and almost nobody does, which is why so many teams find their traffic falling while they are still publishing weekly.
What decays fastest
Anything with a year in the title starts dying the moment the year turns. Tool comparisons and pricing posts decay as products change. Platform how-tos decay every time the interface moves, which for ad platforms is constantly. Trend pieces have the shortest life of all, often measured in weeks.
What barely moves
Definitional content on stable concepts holds for years. Original research holds as long as nobody publishes newer numbers, which in most Indian marketing niches is a long time. Tools hold indefinitely if they keep working. Regulatory explainers hold until the rule changes, then fall off a cliff, which is why they need a review date rather than a refresh cadence.
The trigger worth automating
Do not refresh on a calendar. Refresh on a signal. Set an alert for any post whose trailing ninety-day clicks are down more than thirty percent against the prior ninety days, excluding seasonal patterns you can explain. That list is your refresh queue, ordered by how much traffic is actually at stake.
This is a Looker Studio report over Search Console data and takes an afternoon to build once. It replaces the annual content audit that everybody plans and nobody does.
What a refresh actually means
Changing the date and adding a paragraph does nothing. A refresh that works usually means new data, a materially better answer to the query than whoever overtook you, or added utility such as a template or calculator.
If none of those are available, the post has probably lost its slot for a reason. Consolidate it into a stronger piece and redirect, rather than spending another afternoon polishing something that is no longer competitive.