API could support multiple IDs per http send request.
In the current API, If I have to send out 100 notifications, it would take more than 50 seconds if I were to be nice to your API.
I propose I could rather submit a list of users (i.e. a comma seperated string of users), for up to, say 10 users. Sending the notifications would take 5 seconds instead and produce less stress on your web servers.
Ps. I am unable to use the Group functionality for my use case, as the recipient groups are dynamic on each "run".