Having provided a broad definition of a virtual learning environment, we question the effectiveness of these environments. Do they enhance the effectiveness of education? Potentially yes, but probably not. It would not be honest to claim that virtual learning environments will improve the quality of education or reduce the costs of educational systems. These environments have some potential effects, described in this document. However, the past tells us that it is very difficult to set up the conditions that turn potential into actual effects. Anyway, even if there were no proof of superiority in terms of learning outcomes, the evolution would not stop. The issue is not to prove the effects but to understand them.