It has nothing to do with ads, we use google analytics to track our site stats.

Before we used them, we had a log parser, but going through millions of requests every day was slowing down the site to a crawl so we decided google analytics was the better choice.

Ultimately it helps us understand what pages people are going to the most, what features they like, etc. It’s all aggregated so it’s not like we’re tracking particular users on their paths through the site or anything evil like that.