I wanted my "backend" to be always-on, power efficient, and powerful when headless. The MacBook wasn't a good option because I often close it or leave it unch

I wanted my "backend" to be always-on, power efficient, and powerful when headless. The MacBook wasn't a good option because I often close it or leave it uncharged, and OS X doesn't have as many command line tools available as Debian or other Linux distros. It's also a huge waste of power to use the MBP as a server, whereas the RPi sips power from a cellphone charger. I could have also used an EC2 Micro instance or a Linode, but those are both much more expensive than an RPi for something I don't even use every day.