Can we make profit from FOSS (as a developer)?

Today I had a little conversation with one of my friends, Kusal about FOSS (Free Open Source Software). So I thought to start a conversation on making profit from FOSS...

• Commercial Companies
• They make money by selling services.
• Those services include customer support, product customization, consultancy services, training and selling licences.
• The examples of companies which have gain lot of revenue are,
• MySQL AB
• Major FOSS Products: MySQL
• Revenue: US$ 40 million
  

• Red Hat Inc.
• Major FOSS Products: Red Hat Enterprice Linux and Fedora Linux
• Revenue: US$ 278.3 million

• Novell
• Major FOSS Products: SUSE Linux
• Revenue: US$ 1.2 billion

• Non-profit Organizations
• These organizations do not make profit from their products.
• But you can make money as a developer by working for a such organization.
• But these organizations have lesser number of recruited developers and large number of developers outside who contributes to it.
  
• Examples:
• Apache Software Foundation
• Major Projects: Apache Webserver and lots of related projects
  
• Mozilla Foundation
• Major Projects: Mozilla Firefox Web Browser and Mozilla Thunderbird Mail Client
  
• PHP Group
• Major Projects: PHP
  

• As a developer
• If you are a developer you can still make money there are lot of opportunities.
• You can get some revenue by placing advertisements in your software home page.
• You can promote your other commercial websites using your product or website.
• Your work may help you to get scholarship for higher education.
• Your work will be an advantage on any job interview.

I think "Free Open Source Software" is the best thing that has happened to Software Industry, it is a community service, but by contributing to FOSS you can also make money and their are more advantages too.

This article is "AFAIK" kind of article. In other words based on my knowledge... so feel free to criticise me or add something to this.