Here are three questions you should be prepared to answer crisply and clearly for a job interview:
Why do you want this job? To answer this, do in-depth research on the company. Be able to tell them about what excites you about their product, service or market niche. List the challenges that excite you about the job, and how you plan to tackle them. Talk about how your past experiences give you the tools and know-how to do the job well.
How do we make money? This question is purely to see if you have done your research. Have the answer. If it is unclear exactly how they do make money, with some tech companies it is a bit challenging, do enough research to develop a theory or two and put those forward to the interviewer. Say you have gained some knowledge about potential revenue streams, and would love to hear the actual answer.
Why are you the best candidate? This is always tough, because it feels like the answer is bragging. What this question really means is “What are your top strengths and how will they help you do the best job?” So talk about how your top strengths (hint: These had better be pulled from among the job posting requirements) and experiences will have you quickly doing the job for them.