I could use some quality input on the following topic for another article that I'm planning:
What, exactly, constitutes a good platform?
(http://iliketowastemytime.com/sites/default/files/imagecache/blog_image/draugen_platform_oil_rig_3.jpg)
In a clear cryptomegatrend, a number of leading chains are beginning to be marketed more as a platform than a currency or asset.
1.  What are the minimum essential characteristics to qualify as a "platform"?
2.  Which of the top chains are explicitly making that claim?
3.  Which other chains would also qualify as a platform if they thought about it, and why?
4.  Which of the top chains do not qualify as a platform, and why?
5.  What characteristics/metrics should be used in selecting a platform for a new project?
6.  What links have you seen to any existing articles on this topic?
Don't feel you need to answer all of these questions.  I'll take any profound insights I can get.