It's hard to know where you're going if you don't know where you're at. Knowing where your website visitors are coming from is a critical piece of business intellegence.
The keywords that caused our visitors to find us via Google are hidden from us by Google Analytics and summarized as «(not provided)». TrafficAnalysis reveals a large percentage of these keywords. In order to do so, Traffic Analysis receives data from Google Webmaster Tools and from the crawling services SEMRush and Searchmetrics, so you can still see where your visitors come from.