Work
How quickly a tag stops working
A feed shows the newest posts first, so the rate at which new posts arrive under a tag is the rate at which yours sinks. This is why a tag with a million posts is worth a slot but not most of them.
The Formula
a tag's visible life falls as its post count rises, so crowding is the whole cost of a broad tag
A feed shows the newest posts first, so the rate at which new posts arrive under a tag is the rate at which yours sinks. This is why a tag with a million posts is worth a slot but not most of them.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| N | Posts under the tag | count | How many posts already carry the label. |
| t_vis | Visible life | time | How long a new post stays near the top of the feed. |
What Each Symbol Means
Ncount
Posts under the tag
How many posts already carry the label.
t_vistime
Visible life
How long a new post stays near the top of the feed.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to choose hashtags page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Choose Hashtags, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.