Using this report, you can analyze whether your channels have new or repeating contributors. For example, if you have a high rate of new contributors, this means your channel does recruitment. In other words, these are new people contacting your brand. On the contrary, if the rate of new contributors is low, these are the same people who will contact you regularly.
On social networks you typically seek to recruit a high volume of new contributors. For a community forum, on the other hand, mutual assistance is important and it is not a problem if this channel has regular contributors.
For example, when a channel shows a rising volume of new contributors, this shows that it is recruiting.