There are companies who currently use open source for their business. These companies will need people who can maintain and even update their software.

Companies may also need custom made software to meet their business needs. And they often go for open source software. And this will be another opportunity for the open source community to earn money.

Smart phones are growing in popularity these days. Needs for mobile applications are also growing because of this. Mobile application development using open source software is another way to earn good money.

Many companies choose open source Customer Relationship Management or CRM for their websites because it is free. For example sugar crm.

You can create your own open source CRM and offer technical support for a fee.

Online games and PC games are so popular today. You can create games like these using open source software. And selling these games will definitely give you a good income.

You can also publish a social networking website using open source software. Social networking sites open many opportunities to earn money.for example you can use buddypress and bb forums integrations to develop a scaling social application.

If you are someone who has good knowledge about open source software you can put up a blog and put some advertisements in the blog to monetize it.