They track the web sites that people visit. Other companies practice rewarding self-profiling, people are encourage to register by offering them points that can be redeemed for frequent flyer miles or selected products. Every vendor seems to have a different method for targeting users. Armed with this information you can better select your media vendor and better target users. Until now I had never heard this title.
Online planners are the stewards of a client's relationship with other media.
The online media planner's primary responsibility is to find the most efficient ways to reach or exceed the client's business goals. In short, if you have a product that you want advertise on the web and need help, you can hire an online media planner that will guide you and do the work for you. From a business point of view, I see this as a smart way to advertising on the web. Otherwise you are setting yourself up for failure. The advertising business is a very competitive field.