There are a variety of the models of OER currently in use and many authors have discussed about it. it is possible to analyse these from different perspectives. For example, Down describes the following funding models:

• Endowment Model
• Membership Model
• Donations Model
• Conversion Model
• Contributor-Pay Model
• Sponsorship Model
• Institutional Model
• Governmental Model
• Partnerships and Exchanges 

He also describes technical models, content models and staffing models.  

Please read the article "Models for Sustainable Open Educational Resources" by Stephen Downes at http://ijklo.org/Volume3/IJKLOv3p029-044Downes.pdf