Automattic is testing email marketing to WordPress.com users who have accounts linked to Jetpack, in order to market Automattic products like VaultPress and Akismet. It's the first time I've seen them make use of the WordPress.com <-> Jetpack connection; previously the only cross promotion was through faux modules in the WordPress admin.
Here's a copy of the email with the user information redacted:
They've been running these tests since at least the end of February, as I found an archive of past campaigns from the Mailchimp list (hint to my Jetpack friends: you can hide that!):
The older newsletters aren't as text heavy, so they've definitely been testing the different versions, and I suspect email marketing will become a bigger part of Automattic's strategy for monetizing Jetpack users — by sending users information for other Automattic paid services.
There's a ton of power in having 3 million+ active users. They are probably quickly discovering just how big email can be for them.
Considering that many hosts now bundle Jetpack with their services, this is also fascinating from that point of view. Hosts often offer similar services to Automattic, especially in the form of backups.
If you get an email from Jetpack, I'd love to see it. Right now it appears these are going out to a tiny subset of users. If you click the, “Why did I get this?” link in the newsletter, it says the following:
You are subscribed to this list because you are a Jetpack or WordPress.com user.