So I remember seeing the post with 2 billion gil..and decided I'd try my hand at getting that before 3.0

I've been leveling my crafting and trying to make some money.. I think I've been at it for a good 2-3 weeks and still only made 63 million gil, nowhere near 2 billion goal.. At this rate I'll be happy if I can just make it to 1 billion. How do these people make so much money??