How many words can you pack in an ad?

It is said that Japanese television ads pack a lot of words, of­ten in just 15 seconds

I have had a penchant for wearing a wrist watch with a stop-watch feature. This is an old habit predating the smartphone era. Why, you may ask. While working in marketing and adv­ertising, you are in the business of creating and approving televi­sion spots of a fixed length (it was a practice at least till the 2010s). And it was always a good habit to see if all that a copywri­ter has written can fit into the 30 seconds planned for the ad. One rule of thumb was to ensure that the dialogue and voice­over portion of the ad, when