Both open source and closed source publishers regularly charge by subscription, usually for services necessary to a program's operation. Security is nearly always sold this way. Patching and updating are also behind the services trend.
I've been in touch with the folks at FireTrust, in New Zealand, about their FirstAlert! anti-spam database. (More on that later.) You buy their proprietary MailWasher Pro package once, or download their open source MailWasher Server, but it's the $9.95/year ($2 for the server) FirstAlert! service that makes both go. And it may be that over time, it's that regular update, sold by subscription, that will make the company go, regardless of whether people are using its closed source or open source solutions.
The idea of selling service unites the closed source and open source worlds. Increasingly software needs the regular updates that makes selling it as a service look attractive.
links to the last post are:
Yay! links are good!
This is TOTALLY true. " Its about what works best at what price to solve a particular problem"
I think it is!