There are a few models that has proven itself out for open source projects - here are some of them:

1. Training - As organization adopts open source packages, one of the key areas they require help is in training their team. Many companies routinely hire the creators of an open source project.

2. Support Contracts - Providing a responsive service for troubleshooting issues in the use of the software.

3. System Integration/Deployment Services - Deploying the software in the corporate environment and network.

4. Consulting/Advisory Services - On how to deploy the software and further enhancements and customization.

5. Supplementary Training Material - Books, screencasts, DVD, audiobooks

6. Tested Versions - Versions of the open source that has gone through further testing and compliance.

7. Job board - Once the open source project has reached enough deployments, the specialization would create a community that would be in demand.

8. Hosted services - Take a look at Wordpress.com - which as a popular open source project becoming available as a hosted service.

9. Sell the company - Have a company own the rights to the software/brand, and exit as an entire company.

1. Having advertisement on your open source web project site. However, there are many consideration needs to be taken. Please refer to Financing your Free Software with Google AdSense
2. Build your reputation through open source project. This will increase your chance in winning the bid for contract based software project.

Any way, the most item of having the above 2 to work is, write a good open source web project software, which everyone want to use it.