1. One of the important characteristics of the original Magic game is that rarity is not correlated with game-play value. Common items can be much more powerful than rare item. See – http://www.escapistmagazine.com/articles/view/issues/issue_105/784-Richard-Garfield (great article)

2. The collectible model can address game balance problems by follow on release of items that counter earlier powerful items and letting the market set the price of cards (if all items can be purchased through a common “booster” purchase system).

3. In the West (or at least the US), discussion of virtual items and collectibles neglects the critical role of purely decorative virtual items in many Asian F2P games – items that have no game play function or items that replicate existing in-game items with different art assets.

4. No one has really followed up with Magic’s “booster” model for an MMO – it has a very compelling advantage in terms of reducing the penalties for late entry in the game, if designed properly.