David,

Something else you may want to try are tracking URLs.  If you are utilizing Google Analytics, you can setup tracking URLs that allow you to know which website the clicks are coming from, but also allows you to point users to the same URL/content on the website.

There are a lot of templates out there that can help you to get started using them, but once you do, it makes it a lot easier to track what mediums are driving what traffic.  If you want to get really spiffy, you can start tracking what traffic drivers are creating the most conversions and also start to utlize multi-channel funnels.

If you are interested I would be more than happy to help you get started.

Hope this helps!