The sampling of data is definitely a pain point since we don't have an actual understanding of the data. Since the tool is free, I believe Google is optimizing costs by sampling data and providing us with a fairly accurate view of our site analytics. The mobile aspect of Google Analytics is quite complex to integrate using their SDKs. The web is much easier to integrate with a simple script to add in the header. I would love to see an auto event capture mechanism, like Mixpanel or Heap, so that the setting up of the analytics becomes easier.
