Arguably one of the most evolved areas in terms of how much it has changed. However, you can still pay many thousands of pounds for tracking software or get it for free. The high-end packages do look very attractive and are extremely effective but the need to evaluate how much you will be able to actualy use them and act on their findings is the key to making the right software selection. And now with the advent of behavioural targeting and tracking software the game just gets more interesting.