Note: Originally published on Forbes I was preparing a webinar for my company when I decided to do a little research to uncover the current optimal length for a product or promotional webinar. I started cruising search sites and was surprised by what I found. A global marketing company with eight offices and 350 employees stretching around the globe had posted an article on that very topic. One of the “cardinal rules,” the author stated, was to never let webinars be longer than 90 minutes. They recommended 60-90 minutes and said anything more than 90 would cause the audience to …