Fred Wilson's Principles of Successful Web Apps
carsonified.com
carsonified.com
Is Google programmable? Is Gmail a media and also programmable? Is Amazon playful? That applies even more to the myriad of smaller companies which are successful anyways.
Advice #11 : be cautious of advice.
Amazon might not be "playful" on it's own, but comments like the first one one this item add to the fun: http://www.amazon.com/Mountain-Three-Wolf-Short-Sleeve/dp/B0...
I look at Etsy as an example of a site that tries to hit all 10. Their API isn't read/write yet, so maybe it isn't fully programmable.
We don't see that too much in the marketplace.
Media that can use in-app purchase to acquire more media, too.
Read-write APIs are useful, but proceed with caution. http://friendfeed.com/gabe/82458dfe/api-design-is-like-sex-m...
So far for OurDoings I've only implemented 3rd-party read/write APIs, allowing integration with the Picasa desktop client, ping.fm, and hellotxt. When Pixelpipe approached me about an API I just had them use the ping.fm "custom URL" API I had implemented. But eventually I'll need to make some serious design decisions and create an API that gives read-write access to unique features.