mack - 3:42 pm on Oct 10, 2012 (gmt 0)
If all goes well you will then be able to manually review all registered downloads to ensure they aren't using your product freely when they would have been required to pay.
There will be people who supply a url and use your template on a number of sites, either legally or non paying when they should be.
Another option (I have seen this done before) is to place a 1px1px image within the template and you can then track usage.
Hope this gives you some ideas :)