http://www.slothtrader.com try the free version. If you like it, upgrade to paid. It is visually ugly (sorry Rowan :P) but beautifully simple to install and use.
Yes, your question about linking is correct - if a trade sends you a visitor, /sloth_out.php... in this case, will track how many clicks were generated. If you have a toplist linking to your trades, yes, it will track those as well.