alt Hacker NewsBlizzard runs several popular games where you need to buy their currency before you can buy anything. I don’t know if it’s the case anymore, but Microsoft used to require Xbox Gold to purchase games. Usually this requires locking more up than the purchaser intended to spend.
AFAIK in most games or storefronts with a real-money exchange pipeline, the resulting units are simply not gift-able. Being unable to exchange value with other users makes it qualitatively different.
In other words, you spend regular money for company-points, but thereafter you can only spend the company points on things that cannot be transferred. While there is certainly a cynical aspect to locking up customer funds, it makes it a lot easier to handle things like fluctuating currency exchange rates, and simplifies refunds within the points-store.