Google realized that paper is the best medium to read email, so they'll roll out a new feature called Gmail Paper that lets you archive an email to paper with one click. You'll get the paper messages in 2-4 business days and, best of all, the service is free.
"The cost of postage is offset with the help of relevant, targeted, unobtrusive advertisements, which will appear on the back of your Gmail Paper prints in red, bold, 36 pt Helvetica. No pop-ups, no flashy animations—these are physically impossible in the paper medium."
Google also considered the environment issues and the "Gmail Paper is made out of 96% post-consumer organic soybean sputum, and thus, actually helps the environment".
Related:
Gmail to Fax (unlike Gmail Paper, this one is real)