I tried to explain it here: http://news.ycombinator.com/item?id=3707183 http://news.ycombinator.com/item?id=3707183 More condensed, it's a combination of Apple

I tried to explain it here: http://news.ycombinator.com/item?id=3707183 http://news.ycombinator.com/item?id=3707183 More condensed, it's a combination of Apple not wanting each app re-implementing push (or constant polling), Sparrow not willing to take on the responsibility of being able to access your email, and Google not providing low-privileges access for Sparrow to only be able to see the little amount of data that push needs.