Since Jewels are going to be in game coin, here is a video talking about how in game monetization, which i believe where jewels have huge potential:)
How free games are designed to make money
https://youtu.be/fKK9nVLvhGMThis was a very informative video! I already knew the f2p model was very strong because games of League of Legends use it via micro purchasing so I hope others take the time to watch this short video and really understand how powerful it is.