Hey I'm an employee at shortwave.com (the startup behind this). I totally understand the pessimism - to be totally transparent, this is a marketing campaign to get our name out there.

We're an email company, so why not send "real" mail during the holidays. We're not trying to make money doing this and it's a limited time offer :)

There is really just a couple people with some printer templates, stamps, letters and some hot wax[1].

[1] We ordered a custom wax seal with our logo on it for this (pictures on the website) which I think looks great.