New Theory: Oldest Profession is Appliance Sales

.....and NOT Prostitution (though some may argue, it is our opinion that there is a difference)
Harvard anthropologist theorizes in January Scientific American article that our big human brains are the result of switching from raw to cooked foods millions of year ago.

And "Cooking", as we all know, means there's gotta be a cooking appliance, from which one can conclude the existance of the first Appliance Salesperson.
How was the first appliance paid for?  Let's just say that the Prostitution profession has nothing to be ashamed of.
(May also be evidence of first use of the sales promotion,  the "Layaway"...Badda Boom!)