I would agree with you if there was something being sold, like an easy fix pill that grows your dick. But in the case of the jelqing technique all the information is freely available online, and as I said it requires a ton of dedication - i'm talking 30 mins a day, 5 days on and 2 days off per week, for anything from a few months to a few years (depending on your desired size and speed of gains). No company would be able to sell that exercise program to the masses, it's for the fanatics who truly aren't happy with what they have.
It has taken about 5 months so far. Most of the gains came in the first couple of months but have since slowed down, so I need to adapt my routine. The biggest improvement overall has been erection quality, so it could be that just having a raging boner all the time helped me reach my natural max potential size. Anecdotal evidence suggests that not fapping is beneficial for jelqing, but I don't believe it (and edging and ballooning exercises are just too fun and also provide some gains by themselves).
My girth hasn't changed much, still a bit pencil like, so i'll need to attack that with some girth specific exercises called V-jelqs. I use no creams, only some lube/oil which is necessary to do the jelq properly. I also have a rice sock for warms ups, but other than those two things, that's it. Don't waste money on creams and pills, they do not work (although i'd suggest something like ginkgo biloba and ginger supplements because they are good for circulation). Google "King Pole Erection Tea".