In a recent blog post, Markus "Notch" Persson asked Minecraft players if Mojang could "snoop" on them. He also revealed that there is no tracking other than logins for Minecraft. Therefore, Minecraft has achieved its phenomenal success with almost no game analytics or monitoring (apart from user feedback, of course).
Now, you might be thinking "I don't need no stinking metrics if Notch didn't need 'em!". To which I would ask, "Are you Notch?" Minecraft is a great game and Notch has done some amazing things to bring about its success. However, the planets really aligned with Minecraft to make it something special. I don't think any of us can really hope to achieve the kind of home run success that Notch has had with Minecraft. Our best hope is for maybe a single or a double. So, given that, I really would not want to test my luck and have little to no idea what was going on with my live game. I encourage you to check out the different game analytics and monitoring tools out there and pick one to use before you release your game. Of course, we would greatly appreciate it if you took ours for a spin as well.