Pinterest ADS. Need guidelines

So, I have been marketing my website on various social media sites for quite some time.
I have hard time making a valuable AD campaign on Pinterest.
My pins are doing well in general. I have multiple 10K+, 20k+ pins. However whenever I try to make my promoted pins go viral I fail. It seems like it is almost impossible to give a good start for a pin to go viral with Promoted ADS or, or I am missing something.

If any of you build up repins by Pinterest ADS, can you give me some guidelines….

Pinterest ADS. Need guidelines