how dangerous is network marketing? can i even trust it?

[Pioneer]

while i was looking for a job last week i meet somebody and invited me to join in their company (UNO) i believe they are into network marketing but they offer or show evidence that is way too good to be true, so doubt it, but when i start to search the internet about network marketing it seems that alot of people are really into it.
Now i am confuse, so i need answer or opinions from people who had join or got knowledge about this network marketing.
I also wanna ask what the difference of network marketing and pyramid scam cause i've notice that they actually just look the same. I mean a person will invite somebody and then if he/she join he will also invite somebody and so on...
so please help me cause i am interested to join but doubtful if its worth investing.