Web metrics are the information that companies use to improve their websites. This information can be based on server logs (clickstream data), customer surveys, and external data collected by web analytics firms. These data fulfil different purposes: clickstream data enable managers to answer 'when' and 'what' questions, customer surveys 'why' and 'how'
questions, while reports from web analytics firms contain the external yardsticks that enable normative interpretation of the
many statistics unavailable until recently