Open sourced software should be adopted by business and software community because of the advantages it provides over closed source. While each model has its own benefits, for current businesses a mixed model is the best choice.
The cost of each model is very different; open source is free but usually has to be customized for each company thus adding to the TCO, while closed source has very concrete uses, and almost zero customizability. The best analogy of this is the gum analogy: 'Open-source is like a piece of gum after it's been chewed. It's soft, flexible and has many uses, whereas vendor solutions are that same piece of gum, but pre-chewed (hard and inflexible)'. The cost difference seems to be the most compelling part of Open source, especially towards small to medium size businesses that are perhaps the most cost conscious when it comes to technology investment. The process of obtaining certifications for each computer to put Windows on them is often a costly one, resulting in costs of thousands to hundreds of thousands of dollars.
When compared against the cost of a network admin downloading Linux and hiring developers or outsourcing to a third party the results are surprising. Support for the application or operating system is also a huge consideration company's take into account. It would be a company's nightmare to invest a large amount into an application to put on all their computers only to realize that the company is going under in a matter of weeks. This usually only happens with closed source due to the community not being able to support or develop for a platform (or application) that they don't have the original code. Open source applications inherently create large community bases due to the very nature of the code development (shared).