I'm setting up a web app where a user can post an activity. Each activity needs participants. One of the features I think would be helpful if the owner of the post was notified when another user joins it.
Would there be a negative impact if a the owner was notified if users leave the activity? I ask this because in most social networks today I'm finding it uncommon to exclude the latter but would also think its unhelpful if the owner isn't aware the number of participants in their activity, especially as the activity's start-date approaches.