All HTML links must also be formatted in a certain way, so people stay on a member's self replicating web site, to ensure your members always get proper credit for new signups. All HTML links must be absolute URLs.
For example, if you have an HTML link which looks like:
<a href="page.html">
That needs to be changed to:
<a href="http://www.domain.com/members/~username~/page.html">
When somebody visits the web page, the ~username~ merge field will be replaced with the member's username. This ensures nobody will ever stray from the member's self replicating web site, and the member will always receive full credit for all signups.