Pepsi introduced the 2-liter bottle in the early 1970s and almost a decade later they were still trying to convince people that this was something they should be buying, as you will see in this amazing commercial from around 1978. The commercial itself has a “Welcome Back, Kotter” vibe, with a stereotypical New York accented student who knows all about the economic benefits of this convenient way of buying lots of soda pop at once.