HOW TRENDING WORKS
There seems to be some confusion regarding this. Let's clear it!
This is a 2 step process:
1. A collection of all top messages in 24 hours period is put in 'Currently Trending' list. However not whole day used categories like Good Morning & Good Night are not included in this.
2. Trending PN trigger is activated twice a day - as of writing once at about noon & other at about 9 pm IST. Time gets 1 hour +- based on whether summers or winters. This trigger 1st checks if any of message in above mentioned Currently Trending list has crossed X likes. If yes, then it checks the category of that message. Certain categories like Adult, Status Updates etc are not allowed to trend as of this writing. If category okay then message is trended, otherwise next message is checked. Process repeats until first match is found. If no match found, nothing gets trended.
That's it! Hope it is clear now. We are thinking of a way to show which categories get trending PN in near future.
Thanks for reading!