I invite you to take a look at http://www.stickk.com. Here is their mission:
stickK empowers you to better your lifestyle. We offer you the opportunity, through ‘Commitment Contracts’, to show to yourself and others the value you put on achieving your goals.
Basically you put money down on reaching goals and if you don’t make them you have to start paying your friends or others with whom you have made a commitment contract. This financially incentivizes all kinds of things.
Would this work for spiritual growth? Say for example, a congregant put out a contract that she or he would be in church every weekend unless sick or out of town. Maybe it is reading the Bible or being present in a small group.
I do not believe that this makes sense in the long term. However, for someone that is starting a habit it may actually be helpful.
What are your thoughts, feelings or opinions about this?