RedRegistration v3.0 E-Commerce Edition Description:

Just add a few lines of code to turn any software into shareware. High levels of encryption make RedRegistration very secure. RedRegistration works with any development environment that supports DLLs or ActiveX controls. No additional runtime files are required. Additionally, static C++ Library builds of RedRegistration are available to registered users.
RedRegistration Developers SDK has a very simple interface, documented guide, and a code generator with full source-code.

E-Commerce features allow your payment processor to deliver temporary unlock codes immediately, allowing more time to screen for fraud and deliver permanent codes.

There are no hidden costs, and no per use charges. The license agreement is per-vendor. As a registered user, you may use RedRegistration in all of your applications. The only file that has to be distributed with your application is RedRegistration.dll.