Open source gives a company many advantages over the proprietary dinosaurs, but according to Martin Roesch, founder of the Snort project, efficiency may well be the biggest.
We get tremendous efficiency in our development. The size of our research and development team is very small compared to our competitors'. We use a lot of open source tools, we interact with our community, and have people who are long-time open source users who work here. We use it consistently; it helps reduce costs and achieve a lot of economy. I can't imagine how expensive it would have been to build this company without the open source world. We wouldn't have had the community hungry for the solution when it finally came to market.
There are other ways to develop and distribute software. They just happen to be wasteful and slow compared to open source. And yet many continue to slog through proprietary development because they erroneously believe it's the secret to outsized monetary rewards. They'll learn.