When Shippen first started using transdermal scrotal application it was only once daily (low dose) and as far as scrotal application in general the Testoderm (scrotal) patch was approved for use by the FDA in 1994.
For years Dr. Crisler was using the standard (non-scrotal) once daily (am) transdermal application method for patients that did not want to use injectables.
For some of his patients using injectables he eventually started having them apply a low dose cream scrotally.
As far as transdermal cream (high dose) being applied twice daily (am/pm) sure it was being used but it was far from common and now because of certain doctors raving about it as if it is the next best thing it seems as if everyone and their brother wants to jump on it.....hence the new fad!
Okay, I see your point, but considering that those videos only get around 1k views it doesn't seem that many guys will find out about it and even fewer will try it. So only a fad among a very small group of guys.