In another article covering email's 30th birthday, AllThingsD looks specifically at how email is "the connective tissue of the transactional and social web." Want to sign up for Facebook, Twitter, Pinterest or Instagram? You need an email account. Buying something online? You need email for that as well. And as the social networks themselves are showing with the network digests appearing in members' inboxes every day, email is the channel to turn to for driving deeper engagement and more frequent contact.