Very confused. What are they doing?

[Ginseng]

I've been sitting here watching randomly named mule-like
characters run back and fourth from MH to the NPC Proud Beard,
then to a Taru (I'm guessing to trade), then back to MH. What are they selling?
And why are they doing it over and over again?

http://img8.imageshack.us/img8/770/weirdcopy.jpg

[Zouri]

http://www.bluegartr.com/forum/72586...t-gimmick.html