In all honesty, I'd have to keep it 100 with you and tell you that's not a good reason to start a YT channel.
Now to each their own, if you do start one and you're successful then that's awesome! I feel every YTber who is gaining free products and hair and such and such have worked hard to earn the level of recognition they have.
But they worked hard because they're passionate about what they do. They have the desire to connect with others, to help other people, the personality that goes beyond an in-person experience to an online one, GOOD ADVICE for those of us who don't know what we're doing with our hair/makeup/diet/or whatever. Making a YT channel to simply get free stuff is like starting a fundraiser with no actual goal in mind. Sure, you might get money, but since the money has no ultimate or higher purpose, what good is it?
What motivated me to make videos was the vibe of YT, because it is a COMMUNITY. It is a large force of people that have often times branched off into entrepreneurship, spokespersons, singers, dancers, "gurus", and so on. The reason they receive such incredible accolades is because they have had an impact on their audience.
And maybe getting products ISN'T the only reason that you wanna make videos, but that's all you wrote in your original post so that's all I really could talk about. I'd suggest you'd sit down and really think about the purpose and what it's all about. I'm sure there are plenty of people who made videos simply to get free stuff, but if that's your only motive are you gonna sit up at 1 a.m. in the morning trying to edit and convert your video to make sure it's the absolute best quality....just for free stuff?