The Njoy NPro was my first model, and the NCig was my wife's. Which one do you have?
Now, not to insult you, but a lot of people will mistakenly try to vape the (empty) protective cartridge that comes attached to the atomizer. Make sure you have replaced it with a pre-filled cartridge.
If that isn't the problem, make sure the
batteries are fully charged.
Now, if neither of those two issues is the problem, my next answer will be a little frustrating for you: you need to learn to vape better! Look very carefully at those people in the videos, and you will notice that they aren't doing *exactly* the same thing you are doing. There is a post here to get you started learning better
vaping techniques.
http://www.e-cigarette-forum.com/forum/ecf-library/85612-newbies-proper-inhalation-technique.html
Also, that is only the beginning! There is also the "direct inhale", if you still aren't happy with the performance.
Another thing that effects vapor production is the eLiquid itself. In my experience, the stuff that comes with the Njoy products is pretty lame. It doesn't produce a lot of vapor, and the flavor leaves quite a bit to be desired. You can get a lot of good suggestions for better juice around here!