I received some excellent feedback for my post on freemium's negative impact on video game design. Part of that post was about in-app purchases, and some folks had the impression that I was against in-app purchases as they relate to game design. That is not the case. I don't think that in-app purchases are bad per se, but I do recognize that they have been misused in recent years (especially in freemium games).
If freemium games are littered with examples of 'bad' in-app purchases, then what kinds of in-app purchases could be considered 'good'? 'Good' in-app purchases are the kind that add to the player's enjoyment without being detrimental to the player or to gameplay. To put it another way, game designers should always strive to make in-app purchases fun and fair .
Here are some examples of good in-app purchases. Please note that I am sometimes referring to a particular in-app purchase in isolation from other 'bad' in-app purchases.
The iOS game Punch Quest has a good example of in-app purchases related to customizing the player's character. By default, a player has a limited set of options to choose from (male/female and a few colors). If a player wants to use a different garment color, add a hat, or choose a different face then they can buy an in-app purchase for their character. Their character is not impacted by these selections in any meaningful way, thus maintaining balanced gameplay. People often want to customize their in-game avatar, and this is a good way for devs to fulfill that desire in a profitable way without resorting to tricks.
Having in-app purchases that allow players to buy new songs or additional levels to play can be a good way to provide ongoing customer satisfaction. Magic Guitar comes with several songs preloaded, and users can purchase additional songs that they wish to play. These types of in-app purchases help keep players engaged in the game without going into addiction territory.
Another way to make use of in-app purchases is to let users unlock all of the levels/chapters in the game. Rock Runners, for example, normally requires users to complete levels in order to unlock new levels. There is an element of chance and choice to how its game map works when users unlock levels. An in-app purchase that lets the user unlock all levels is a good way to balance the needs of skillful players (who can earn their way to all the levels) and the needs of less skillful players (or players that don't have quite enough time to master the game). The latter can still gain access to all that the game has to offer, but without any significant sacrifice in game balance or fairness.
Folks, in-app purchases for games aren't all bad. In fact, some of them can be quite good for devs and players alike. Just remember to keep things fun and fair.