Active buttons in the subject line

This morning I waded into a twitter discussion with a bunch of folks about some issues they were having with delivery to gmail. The discussion started with a blog post at detailed.com describing how some senders are seeing significant drops in open rates. I thought I’d take a look and see if I can help, because, hey, this is an interesting problem.
I signed up for a bunch of the mail that was seeing gmail problems and discovered that one of them had the confirmation link in the subject line. How cool is that?

I’ve known about the Gmail subscription line functionality for a while, but this is the first time I’ve seen it in the wild.
The action is in a <div> tag at the bottom of the email. Gmail has been allowing actions in subject lines for a while, this is just the first time I’ve seen it used for subscriptions. It’s so cool.
Want to add one to your post? Instructions are available from Google on their Email Markup pages.