> No 3rd party analytics service can provide more accurate data than server logs. None.
Google Analytics provides information that goes far beyond what the server logs can tell you. The logs will give you the most accurate view of the requests to your server but that's all. You can't get insights about bounce rate, behavior, goal completion, conversion rate, etc. from server logs. To rely only on mining server logs would be a huge step backwards for a business.
If each request has a session cookie in the log it's easy to track a user's movements through your site, so you can figure out bounce rate, conversion etc no problem. Things like Piwik have pretty dashboards to generate whatever reports you want from server logs.
Piwik looks interesting. I'm playing with the demo right now. It does look like they support goals[1]. I can't know for sure how effective it is but I will concede that log analytics is more powerful than I believed.
Designing good session identifiers for logging is not trivial. More importantly, with a lot of events happening in javascript, a lot of user interactions are occurring beyond the visibility of your server logs. Tracking js events is also clearly possible, but again, non trivial. I've been in more than one situation where we trusted GA more than our own logs.
Some stuff, but if you want to emulate GA events you'll have to also implement some additional frontend code and a backend to log those events. I hope this is the direction that we see analytics moving. The information analytics provides developers is great, but I don't like the fact that this information is usually given to multiple third parties by using their analytics engines.
No they're not. As an example, bounces are commonly the last page where the user left without doing anything. How can you tell that from a simple server log line that says the page loaded? You cant see if they clicked on something or how long they read the page or what other actions they took.
Most sites today also go far beyond basic pageviews and track all kinds of events on the page like scrolling rates, reading time, what other headlines you clicked or hovered over, etc. This is not possible without JS tracking.
Google Analytics provides information that goes far beyond what the server logs can tell you. The logs will give you the most accurate view of the requests to your server but that's all. You can't get insights about bounce rate, behavior, goal completion, conversion rate, etc. from server logs. To rely only on mining server logs would be a huge step backwards for a business.