My older son has been engaged with this - mainly DoTA2, CS:GO and H1Z1. He has had a fairly limited budget of real cash in (a few 10s of pounds) - and has taken

My older son has been engaged with this - mainly DoTA2, CS:GO and H1Z1. He has had a fairly limited budget of real cash in (a few 10s of pounds) - and has taken (and lost) significantly more than that in game through tournament prizes, trades, gambling & drops. My initial impression was rather negative - but I do concede that it has acted as a kind of 'Kerbal Space Program' for markets and gambling - including the spectacular explosions. He now has a far better understanding of supply, demand and timing, along with a healthy respect for probability and risk vs. reward. It may have worked for him because of limited funds (have to go in thru' my card), and there were things inside the system (knife skin) that he really wanted to acquire. I did, however, get him to name that knife 'SSD' in honour of what he could have bought if he cashed out.