User blog comment:Majesty1/Trading Units Campaign/@comment-45.58.89.196-20150903000042/@comment-26455864-20150903002612

Well, doesn't that mean that once you buy enough gems, you no longer need to buy any more? The regular summoning is a much more dependable source of profit because people will keep summoning for units they want, rather than buy the unit they want and not buy any more gems.