The token is not pegged to some dollar-valued fixed amount of that service. Using the air miles analogy, it's like instead of purchasing a fixed number of miles

The token is not pegged to some dollar-valued fixed amount of that service. Using the air miles analogy, it's like instead of purchasing a fixed number of miles, you are purchasing some percent of the total miles that the airline will fly, and are free to sell those to people who want to travel later. It's theoretically a good investment because it will not be possible for anyone to fly on the airline without buying air miles from someone who participated in the ICO. For example, if you think that the market for filecoin file storage is going to be bigger than $200 million, then it makes sense to buy their tokens in the ICO.