1. Was there an investment of money? (money is actually broadly defined to mean anything of value)

2. Was there an expectation of profits from the investment? (this is easy to prove because it's the opinion of the investor)

3. Was the investment of money in a common enterprise? (this means are the interests of the investor and company aligned, or does the investment go into running a business)

4. Does profit come from the efforts of a promoter or third party? (This means is the investor mostly powerless in having their investment go up our down in value)

In your WoW example:

1. Yes

2. Probably for someone

3. Yes, the money is used to develop the platform

4. Yes, if Blizzard hypes their coin or if you can trade it on an exchange

I think the biggest difference between an ICO and a digital good is that ICOs are traded on exchanges. If you buy a digital good and can only use/redeem/trade on the company's platform then it is not a security.