Day to day, we encounter many models in technology and business(both digital and physical). Some of them captures our attention because of their uniqueness and novelty. Below models fascinates me, it solves a problem both in producer and consumer side. For now, I just name this as a Win -Win Model.
Recaptcha: Recaptcha creates a model, mutually beneficial for google to translate books, improve their OCR(Optical Character Recognition) and for site owners it helps to avoid spam and bots.
For further read - http://www.google.com/recaptcha/learnmore
Stanford Online AI Class: Another similar model we see from the Stanford Online AI Class. Artificial Intelligence classes are automated. Ranking questions, assigning homework and grading are done via AI systems. For a student it is useful to learn great concepts from the veterans of the field and in-turn they help the AI system to measure its teaching and continuously improve.
(Now, new classes moved to Udacity - http://www.udacity.com/ )
Reference - http://singularityhub.com/2011/08/18/100000-sign-up-for-stanfords-open-class-on-artificial-intelligence-classes-with-1-million-next/