Disclaimer: Although I work on the What’s New feed in Windows Live Spaces this should not be considered an announcement or precursor to an announcement of upcoming features of any Windows Live service.

Yesterday, I got into a debate with Yaron about whether Facebook has done enough to allow applications built on top of the Facebook platform to feel to end users as if they are part of a unified whole instead of merely being bolted on. I argued that they had, while Yaron felt otherwise.

The next time I logged into Facebook, I noticed the following which I hadn’t acknowledged up until that point. See if you can figure out the problem from the two screen shots. Mouse over for a hint.

The problem with building a platform on top of an existing application is that any problems users have with these platform applications ends up affecting their perception of your application in a negative way. How many people care that 70% of Windows crashes were caused by buggy device drivers that were for the most part written by hardware manufacturers and not part of Windows itself?

Recently I’ve seen a rush by some Web sites to jump on the platform bandwagon without clearly understanding how much work and how different a thought process it actually takes to get there. It will be an unfortunate shock for companies when they realize that it isn’t simply about chasing after feature sets. Building a platform is a holistic experience which includes getting the small details right, like giving users consistent opt out choices for the data they get in their news feed not just providing a bunch of APIs. Facebook is one of the few online services that gets it like 90% right and even they mess up on some things as I’ve pointed out above.

Think about that the next time someone shows you a bunch of APIs and tells you they’ve turned their Web site into a Web platform.

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