[amirmc]

From the original announcement [1]:

"Today, we are introducing schemas in emails to make messages more interactive and allow developers to deliver a slice of their apps to users’ inboxes.

Schemas in emails can be used to represent various types of entities and actions. Email clients that understand schemas, such as Gmail, can render entities and actions defined in the messages with a consistent user interface."

I haven't looked into this in any depth but it doesn't necessarily seem Gmail specific (a good thing) but it does mean even more clicky buttons in an interface where I can't easily see what those buttons actually do (less good from a security/phishing standpoint).

[1] http://googleappsdeveloper.blogspot.co.uk/2013/05/introducin...

[sgrove]

That may be why they've made it a partner-only program, and why they control the interface for rendering each schema (that they specifically choose to support). While frustrating, it's an interesting point to consider.