We often utilize the JustGiving page for events or campaigns that do not have fundraisers. This means that no one is notified when a donation is being made. Because of this, I don't know when gifts are being made and don't always quickly acknowledge them because of this.
I also believe this would be helpful even if there are fundraisers as the organization is the one doing the processing and acknowledgement.
Thus, the idea would be to have an option you can mark for each campaign or event run indicating you'd like to be notified when there is a donation or being able to list multiple email addresses to notify like a donation form in NXT.