I'm sure there are many reasons, but this is the one I'm thinking about today as I deployed Fargo 2.

Now that I have my server running in Node, and deployed on Heroku, adding more server capacity is as simple as it can possibly be.

I love this power, never had it before. Deploying additional instances was always a huge process. They've really factored the UI so that even for a geek like me, there's no effort involved. See how it works, it'll make you laugh.