Google Analytics is ubiquitous, not least of all because it’s better at what it does than most of the alternatives. Also, it doesn’t require any install or maintenance. And it’s free. What’s not to like? Frankly, not much, but if I had to nit pick, I’d note that the worst part of Google Analytics is the ga.js script that does the actual tracking of content. It’s not bad, in and of itself, but it t