1. You don’t need to edit HTML code to include scripts
Depending on how your website is organized, this could be a major tasks, especially if it contains lot of static HTML pages. Adding script code to all of them will surely take time. If your website is based on some content management system with centralized design template, you’ll still need to be careful not to forget adding code to any additional custom pages outside this CMS.
2. Scripts take additional time to load
Regardless of what Google Analytics officials say, actual experiences prove otherwise. Scripts are scripts and they must take some time to load. If external file is located on a third-party server (as it’s the case with Google Analytics), the slowdown is even more noticeable, because visitor’s browser must resolve another domain.
As a solution they suggest putting inclusion code at the end of the page. Indeed, in that case it would appear that page is loaded more quickly, but the truth is that there’s a good chance that visitor will click another link before script is executed. As a result, you won’t see these hits in stats and they are lost forever.
3. If website exists, log files exist too
4. Server log files contain hits to all files, not just pages
5. You can investigate and control bandwidth usage
Although you might not be aware of it, most hosting providers limit bandwidth usage and usually base their pricing on it. Bandwidth usage costs them and, naturally, it most probably costs you as well. You would be surprised how much domains (usually from third-world countries) poll your whole website on a regular basis, possibly wasting gigabytes of your bandwidth every day. If you could identify these domains, you could easily block their traffic.
8. You can find out about hacker attacks
9. Log files contain error information
Without them, in general case, you don’t have any information about errors and status codes (such are Page not found, Internal server error, Forbidden, etc.). Without it, you are missing possible technical problems with your website that lower overall visitor’s perception of its quality. Moreover, any attempt to access forbidden areas of your website can be easily identified.
10. By using log file analyzer, you don’t give away your business data
And last but not least, your stats are not available to a third-party who can use them at their convenience. Google has bought all rights for, at that time, popular and quite expensive web statistics product (Urchin), repackaged it, and then allowed to anyone to use it for free. The question is: why? They surely get something in return, as Google Analytics license agreement allows them to use your information for their purposes, and even to share it with others if you choose to participate in sharing program.
What could they possibly use? Just to give few obvious ideas: tweaking AdWords minimum bids, deciding how to prioritize ads, improving their services (and profits) – all based on traffic data collected from you and others.