Non-invasive collection of data is presented. A server segments a web page into regions and sends the segmented web page along with a data collector program to a client in response to receiving a client request. The client displays the web page and loads the data collector program which initiates particular event handlers to monitor user event activity corresponding to the displayed web page. When the user performs a user event, such as moving his mouse into a particular web page region, the data collector program collects user event data and associates the user event data with the particular web page region. When the user event is complete, the data collector program sends the collected user event data to the server.