It's literally just drop shipping

Don't run any inventory. Just take orders on a front-end website. Then buy at wholesale rates and resell at retail prices, while trying to make a margin based on the difference between the margin and the cost of advertising. It works great if you're able to get a bunch of free publicity. So you'll typically see these guys "networking" in hopes of doing an impromptu sales pitch in front the largest crowd possible. Or doing stunts to get literally anyone to look at them.

Amazon is a multi-trillion dollar industry that's functionally built on the idea of drop shipping. Jeff Bezos is just the richest incarnation of those insufferable frat-bros trying to sell you bitcoin.