I have gained substantial successes in running an Online/Onsite learning model with my students. Achieving a 83% retention rate of registered participants was huge for me.
Our main challenge was getting prospective students to consider techy learning. What with slow internet and even access issues. We had to create an environment that allowed some to learn along without fully having a grasp of the technology.
We learned that many new things can be learned online. People generally lacked the discipline to study online as it is mostly self driven.
A blended approach enabled the 'classroom' feel and enhanced participation to the end.