Like all these multi-level-marketing scams, the scam part is that you have to buy your stock from the company/from your "upline", and then whether or not you make money depends on you reselling your stock.

John Oliver did an excellent video on the overall topic. Definitely worth the watch.

MLMs can be actually viable jobs for a very select few of people. Not entirely unlike how you can theoretically make money at a casino. There need to be winners to the game once in a while, or else no one would play. The game is just rigged wildly out of your favor.

The general structure of an MLM as I understand it is sort of a cross between a wholesale job and playing a mobile gacha game. Unlike a normal business where you purchase stock to match your demand, and only stock items that actually sell, an MLM contractually obligates you to buy a certain volume of stock, and each shipment is essentially a lootbox full of who knows what. It then becomes your responsibility to get rid of the stock any way you possibly can.

When you buy all that stock, you are not buying it from a factory or a warehouse. You are buying it from another person in the same position as you, one layer up. They are also playing the lootbox gacha and trying to get rid of all the crap. Except, hmm, now they have at least one person beneath them who is contractually forced to buy from them, and can't select which stock they're buying. Gee, I wonder what you're gonna be getting...

Whenever you actually do manage to sell something off, a cut of that kicks back to the person who sold you that stock. And a piece of that kickback goes to the person who sold them that stock, and so on, up and up.

The real money in MLMs is having so many people beneath you that the kickbacks start adding up into significant income. This is theoretically achievable. But it requires a very specific kind of personality matrix who is not squeamish about being a little cut-throat to get ahead, and generally requires a significant investment where you are going deep into the red just for the opportunity. And even if you do make it there, you have to accept the knowledge that your profitability can only exist necessarily because of the existence of many people beneath you all spinning those slots and losing the rigged game to the house (who by this point is you).

Okay, so, it's not technically a scam. It's an MLM. The salesman has to buy the stuff they want to sell up-front, and then they have to try and sell it to people. If no one wants to buy, then they're stuck with a whole bunch of whatever--knives in the case of CutCo/Vector--and out the money that they spent. If they happen to be an exceptionally good salesperson, then they can sell everything they purchased, and use their profit to buy more, and sell more, etc.

The issue is that the knives aren't particularly great. They're solidly 'okay', and that's about it. But despite being just kind of okay, the prices are on the higher end. That is, you can get Global or Shun for a similar price, and Global and Shun are both quite good. So if you're a serious cook, your going to spend the same and get better knives. If you're a typical home cook, you're not going to see the value in spending that much on kitchen knives.

But! The real money is in convincing some poor sucker to buy his stock to sell from you. You buy from your supplier, and then you sell at a markup to some other poor schmuck that then has to sell knives at either a higher cost or lower profit margin to someone else. It's a game of hot potato, and the person holding it at the end gets burned.