This is flat out the best bang for your buck when it comes to url rotating and link tracking. You could get a, "Free URL rotator" I'm just going to be honest those work but they have ads and when your wanting to actually building a email list the last thing you want is your targeted traffic going to your competitors.
I really like clickmagick and they offer a free 14 day trial. Make each click more profitable. BIG...BONUS...more then just url rotator and click tracking Clickmagick has pop up windows, timers... A lot of fun tool to take charge of your online campaigns.