A white paper lays out the argument in more detail. In it, PacketTrap refers to commercial open source as "proprietary open source" and identifies 21 startups--from ActiveGrid to Zimbra--that it puts into that bucket.
What does Goodman think is the right approach? His own, of course. PacketTrap is a commercial software company that integrates open source network monitoring and management tools into its own PT360 Tool Suite. Rather than trying to manage an open source project as, say, MySQL has done, PacketTrap leaves project management to the open source community and concentrates on developing a commercial platform that works with the code that community delivers, such as Nagios for network monitoring.
PT360 is in beta testing now. It's aimed at the mid-market, though large companies such as Boeing, Home Depot, Pfizer, and the U.S. Navy are early adopters.
A basic version PT360 is free, while a professional version is due in the next few weeks. This so-called "freemium" model-- give a product away, then charge for a better version -- has its own critics.