"Is email dead?" asks @Graham_Walsh (via @nigelwalsh @leebryant ) noting that Ben & Jerry's are stopping their newsletters, and now using updates on Facebook & Twitter.
Email has always been a poor medium for broadcasting news, for several reasons.
Email is used for delivering many different kinds of content, ranging from important to rubbish. For most people, newsletters (even from companies we are interested in) are considerable less important than direct messages from customers, colleagues and friends, some of which may require an immediate response. Therefore even the most interesting newsletters are likely put aside for later reading.
Many of us receive hundreds of legitimate email newsletters - from an assortment of companies and societies and other organizations we have some vague association with - as well as loads of more spammy stuff. I have set up an automatic filter for the regular ones, which go into a folder called Newsletters, where they may sit for weeks or months before I find time to look at them. Many get deleted unread.
Traditional newsletters contain several items, but this is problematic on email. Most people won't scroll down beyond the first page without good reason. (This was a problem for a company I once worked for, which used to sell advertising space at the top of its newsletters to other commercial organizations, with the result that some readers only ever saw the advertisement and not our own content.)
There is also a design problem. Email clients are generally less sophisticated than browsers, and newsletters that look fine on one computer may be almost unreadable on another. As for reading a traditional newsletter on a mobile phone or handheld device - forget it. (Maybe the iPad?) So people end up producing text versions and HTML versions, and it just gets more complicated without actually solving the problem.
Finally, there is a problem with organizational innovation. Many people who claim to be leading-edge technologists seem mysteriously attached to email as a general-purpose communication mechanism, and reluctant to use the wide variety of alternative mechanisms that might serve a particular purpose more efficiently and effectively - not just when communicating with customers (who might be slow to adopt newer alternatives) but also with their own peers (who have no such excuse). Email becomes a regressive standard for all forms of communication, and there is little willingness to gather evidence about its effectiveness.
There is an expectation that corporate IT will drive innovation in matters technological. But in many large organizations I've worked in, it is the marketing department that is is more likely to drive this kind of initiative. The use of Facebook or Twitter may be a tactical initiative, adopted as an experiment and abandoned if the results are disappointing; but what I'd see as strategic for consumer-oriented marketing is having a flexible communication platform with strong feedback loops to support detailed customer analytics, and that's what I'd expect corporate IT to provide.
Or you could just stick to email, on the grounds that this is safe and familiar to all - business IT alignment interpreted as keeping IT inside the comfort zone of the business.