The "means" by which you sell your product would define whether it is "direct sales." I wrote this article based on what direct selling means today.
It could definitely be argued on a rudimentary level that direct selling = any sales that occur face to face outside of a retail establishment.
Prostitution is the world's oldest profession. Pimps may be the pioneers of direct selling. I, of course, was not going to go there in this article. :)