The key codes will assist you to track the volume of traffic to your ads and the conversion rates. Armed with the information, you can easily decide which promotions are doing poorly and do require some improvements and which are doing very well. You may choose to use some unique key codes for each ads site to make comparisons easier.
It is also advisable (if you know how) to find ways to set up many data fields to compare different types of advertising whether Offline or Online and to make informed decisions based on the data you collect.
These are the only ways I can think of right now by which you can set up a system to organize and track your advertising. Best wishes.