It depends on the 'type' of stats you want to accumulate to be honest and, more importantly, how many different types of sites you have.

If you are just wanting to break the traffic/sales down by two or three different types of site, free site, aen, tgp etc than just sign up for more than one account at a sponsor.

If you need more in depth stats then its going to be a third party script you'll need.

You could also check out an application like http://www.statsremote.com

Regards,

Lee