The ability to see what keywords are working, how many people click each link (which gives you insight into which links get clicked more), who comes from where etc This makes it easy for us as we have limited resources but still want good results! I think that this could be made easier by having some kind of reporting system so once your campaigns go live or start running they can easily tell when things aren't going well/why certain pages weren't performing better than others - not really sure why there isn't one already? Seems like such simple stuff with all these tools available now!! It's great seeing data about our website performance over time using Google Analytics reports and then being able to drill down even further within those stats via specific tabs e.g Pageviews / bounce rate & referring domain statistics.