the problem with long answers is that you might get cut off by the interviewer, and then you'll never get a chance to get back to the rest of your answer. that happened to me with another question. actually, with a lot of them...my interviewer often seemed to think of a new question based on the three words i had just said. he would jump in and then i never got a chance to finish my answer. so my advice is to make sure the most important parts of your answer fit into the first few seconds, THEN go back and elaborate if the interviewer lets you. You want to say: My reasons are A, B, and C. The reason/example for A is...the reason/example for B is...the reason/example for C is... instead of "My reasons are A, and here is the reason/example, and B, and here is the reason/example, and C, and here is the reason/example. That second way means you might not ever get to C. (or B. or the reason/example for A...)