Some examples of the reasons for real changes on readers-per-copy are shown below:
Examples of sudden changes:
- Heavy promotional activity (e.g free gift)
- Price cuts
- Major changes to editorial format
- Sudden losses or gains in circulation
- Seasonal factors
Examples of gradual changes:
- Awareness of new titles can take time to grow
- Long-term expansion or contraction of circulation
- Changes in profile (e.g ageing readership)
- Launch and closure of competitive titles
- Impact of digital media
There are many other possible reasons why readers-per-copy can change over time.
A summary as to why publications have different readers-per-copy can be found
here.