Black Gold will utilize an interesting revenue model. The model, however, has caused a bit of confusion as to what players are actually paying for. Snail Games has sent over a nifty graph to explain that players don't actually pay for extra time in the game. They pay for extra chances to gain great gear.
The so-called "Black Gold Time" is actually "extra loot". Users don't have to pay for the time they've played, but for additional chances to get this bonus. Non-VIP users have 2 free chances to obtain it. They can either choose to take it for themselves or sell it to other players.