Shipnik is neat, but it seems like something designed to be a honeypot.
I'd like to be a vendor some day, and as I sit down and just think about everything... Well, I certainly can't wander into a post office every few days to drop off a bunch of packages all across the country. I'd be recognized.
Blueboxing, of course, is the main way to do it. But that means shipping has to be paid; stamps work but are less than ideal.
you should purchase some guides and read up on how vendors ship product out if you're even remotely thinking about becoming a vendor lol