Then I went to buy it and surprise, after you pay for it you gotta download impulse.
Because Multiplicity is used often in business deployments like this, it is one of few apps that do not require Impulse.
There are several ways that our customers can retrieve their software and licenses that they have purchased. Keep in mind that trial versions of our software are not upgradable to the full versions by entering a product key, and they must be uninstalled and the PC rebooted before installing the full version of any app. Here are the possible options (NOTE: Not all applications are available under each option):
1.) Go to https://www.stardock.com/support , enter your e-mail address to have your product info sent to you at that address.
2.) If you have a Stardock.net account, visit the following site and click the link for the appropriate application/theme: https://forums.stardock.com/account/regs If you're trying to get a theme/skin/etc that you purchased through WinCustomize, this is the best way to go.
3.) Impulse (which as you stated isn't really an option in this case, but I'll list it for others who may be curious).