I had a FB AD rejected because it didn’t meet the “less than 20% text rule.” There were few words, so I was surprised. I uploaded it to the Facebook Grid and realized that it wasn’t an issue of how many words, or characters, but where the words were located.
It turns out that each box in the grid represents 4% of the image size. So, text that enters two boxes, covers 8%. The headline on the AD that was rejected was on one of the horizontal lines, so the FOUR words were in EIGHT boxes, or 32% of the space.
I redid the graphic, making sure the text was not overlapping boxes, and the new AD was approved in less than 10 minutes.