For instance, I recently got a card from a popular trade publication that will remain nameless , asking if I'd like a free subscription. I completed the required form but was then informed that I would be on a waiting list and would get its email newsletter in the meantime. They basically consist of links back to the publisher's Web site, perhaps with a summary paragraph on each story. Oh, and lots of ads. This is awesomely Clueless.
Email is a far more personal medium than print.
It demands a different writing style. Also, email and print are very different media. The best email newsletters don't just offer news, but opinion and wit. They leave you thinking. And they don't just leave you clicking back to the author's home page.