Is it possible in CiviContribute to track multiple external (non-CiviCRM) sources of contributions to a single form?
I've used other systems where I could create a source code for, say, a banner ad and apply that source code to the donation form URL. I could then create another source code for donation links within an email. Sometime later, I'd be able to pull up a donation report for that form and see that there were X number of donations that came in from the banner ad, and X number from the email.