Platinum has no monetary value. You can convert money into platinum, but you can't convert it back. So platinum is not real-world currency. When you complete a free offer, you aren't getting paid with a real-world currency. You can only buy virtual items with plat, so it is a virtual currency. Just like gold. Like i said before, there is a gold-value for plat. It's whatever the amount you can officially liquidate it (in this case, 1 plat = 1,000 gold).

Another thing: When you buy plat, you can also buy gold. If you buy $89.99 worth of plat, you can liquidate it all to 1.7 million gold (though it wont be a smart move). Though most people use their plat for all those reasons Otatotomustam mentioned in his rebuttal of my post, you cannot use it for buying things in the CS (the #1 place where players buy items). You need gold for the CS. You need gold for trades. Gold is a precious currency.