Originally Posted by
Jennestia
You have to populate the shop with a reason to buy it, and it's usually something you can't get in normal gameplay and is usually better than what you can get.
For example, Cash Shops share one common theme:
Hyper versions of normal potions. Say Hi-Potion restores 1,000 HP, the cash shop version would not only restore more than 1,000 HP it would have added effects like HP+4% or an additional HP restored over time for x duration -- That's a lot better than what you can get in normal gameplay. Gear wise, even vanity items that add more stats would make you better than those who don't utilize it, because no matter how you slice it, you're getting more benefit over time versus someone who doesn't use the shop.