Actually it is easier to make huge sums as an affiliate rather than as a vendor, especially affiliates with large email lists since these can ask for 90% commissions from vendors and will get them. A couple of days ago we got a blast from one such affiliate, who made around 280 sales in a day. The result? We (10%) got just over $1,300 which is good but nothing to scream about. Them? (at 90%)? Around $12,000.
Also keep in mind that vendors will typically have much, much larger expenses than affiliates. A good copywriter will cost you $30,000 - $50,000 plus royalties, and you'll need to add $10,000 - 30,000 in product research, creation, video, website, etc... so you start out with a massive hole. And then the 10% or 25% commissions that you earn will often be divided further (e.g. copywriter royalties, royalty to the health expert if you retain them, etc...)
I'm not saying that being a vendor is not profitable; I wouldn't work as a vendor if it wasn't...but people often hugely underestimate how potentially financially risky and costly being a vendor is. It is definitely NOT easy money as many make it out to be....