I've long thought this. A well-timed exclusive of enough quality will garner an extraordinary level of hype and far higher sales than if the title had been multiplatform. The internet goes wild over these things, even for largely middle-of-the-road games, and when accompanied by good reviews and solid word-of-mouth, a dev can hope for both high sales and a cut in development costs (including time) for not having to produce their title across multiple platforms. Further, such titles can gain extra support from the platform holder who may be keen to keep the high selling game on their system, ensuring it is not only a centre of hype regarding their product, but another reason to purchase their machine. So, lower development costs and subsidies from the platform holder (perhaps in the form of marketing or similar) coupled with higher than normal sales can perhaps guarantee an overall higher profit for the developer in question.
That said, titles of this type are in the minority. Most games will almost always sell more -- in most cases, much more -- over multiple platforms. The target sweet spot is very hard to hit on a single platform, and far too random a situation for most developers to gamble their future on.







