I do and have been 99% satisfied with making buying decisions based on Youtube videos or info here and my perception on it.
Only one f**k up was the Dutch Bladeworks - Xerxes. Watch Nick Shabazz video on it, loved it, once it arrived and opened the box I flipped it about 100-150 times and hated it. The knife was not at all what I expected in terms of ergos, hand feel, etc, but this happened only once. All other times I've been 100% happy since before researching a knife or info video I already have a good idea in terms of specs and knowing exactly what type of knives I like and prefer. For example I like flipper that run on bearings or PB washers 0.3mm thick on titanium framelock or backlock, I hate liners, spyderholes, no jimping knives, slippy horrible flippers, I am ok with thumbstuds, I like my blade 0.14 inch or thicker and I like supersteel tanks made of Elmax, M390, CPM 20CV, 3V, CPM M4, CPM S110V, S125V (if you can find it), REX 45, S35VN, 10V, etc... So when I find a knife that meets my likes and preferences I already know 50%+ that I will either like it or love it. With review videos it helps me to discover small details and also hear what other knife guys have to say.
Reviews are very helpful and helps users to make sound financial decisions in regards to their knife purchases. When you feel that for each $1 you spent for your knife, you got minimum $2+ worth of quality knife and service warranty customer care = that's a win in my book. This had been my personal experience with Hinderer knives, Paragon Knives - Asheville Steel, Benchmades, ZTs...
Making wise financial decisions is important. Buying a knife is like a short-term marriage with your tool. So use all the resources available to make the best decision.
I've been very lucky and happy getting positive comments from my Youtube subscribers regarding watching my review videos and then making a buy decision. Some did mention they don't care about the 5 and 7 minute long reviews, they only care about the specs and close-up looks of the knife. That's how they make buy decisions. So I am re-arranging my videos and also putting out some 1-2 minute closeup specs only videos. Everyone has their own decision-making process.. These videos just widen your visual perception as a user.