Michael Sippey of Twitter:
You’ve probably expanded tweets before to play videos from YouTube or see photos from Instagram. Now, a diverse and growing group of new partners like the The Wall Street Journal, Breaking News, and Time also deliver rich content inside tweets containing a link to those websites.
This is a very smart monetization strategy. It’s completely natural, doesn’t require Twitter to alter their product’s core philosophy, and isn’t intrusive to privacy unlike many advertising strategies. Via John Gruber.