Quote from Runningbear:
Another option is to supply your systems coded with the code encypted and time limited. The code simply stops working after a given period and if they wish to continue using it, they have to pay you for a working version of the system.
This is pretty easy to do. And I know you can do it in esignal and tradestation.
Runningbear
I agree with Runningbear..
Have it coded to time out at a specified time. This will the system buyer and opportunity to test for themselves.
As an alternative, you can also contact different brokers who will trade it for customers. Of course, they will be some marketing involved, but it is an option.
I know a couple of developers who have done this. You can PM me if you need more information.