It is very easy to think of Internet Marketing and act tactically. However, all your activities with search engine optimisation and email marketing should always be driven by Website/business objectives and this needs to be the subject of continual control. You may know where you want to go but how can you tell if you have got without some form of measurement.
Jim Sterne in his article 10 Steps to Measuring Web Site Success gives some interesting pointers on how you can make your website even better. In a nutshell it comes down to talking to the people who ultimately matter: the stakeholders and constantly measuring the success of your site.