Why do you want to join a start up?

As the placement season is about to commence, many start up companies will be visiting various colleges for recruitment. One of the most important and inevitably asked question by start up firms is that why do you want to join a start up company?

There can be many possible answers to this and everyone's reason for joining start up is different. Here, I am providing you with a basic idea as to how to answer such questions. 

Your answer should revolve around the start up and the tasks and environment in which it works. You should love challenges and working in informal and disorganized sector (or at least pretend that you love doing it) if you want to apply in a start up firm. By working in a start up you will definitely groom your personality but this is just a small reason for joining start up firm. You should say that opportunities are tremendous in start ups and responsibility and accountability for task is given which is the best part. You can say that start up companies entrusts upon the intern/employee and gives them main field job and so, one gets chance to explore all the new horizons and use one's capability to the best to carry out tasks. 

I am writing following few lines in the first person so that you use them as it is if you wish to.
"There is freedom to work on our own in most start ups and i would like to contribute to the growth of the company by using my ideas and past experience. The kind of learning curve in a start up firm is very steep which is the biggest motivator for me to apply for this position."

Your answer should be somewhat similar to this. Don't revolve your answer around only personality grooming and holistic development. Include that in your answer along with other key points. 

P.S.: These are just few points which can be considered. Please don't think that only these points will help you get through the entire procedure.