This is a common interview question that pops up and is one that pretty much sums up the point of a job interview in the first place.
In other words, what can you do for our company?
Essentially the company is looking to hire someone to solve a problem or fill a need.
It can be very easy for people to forget this when they go into an interview and to focus on what the company can do for you.
Here are some suggestions to ensure you structure the whole interview to focus on what you can do the company and hence, why the company should hire you:
1. Answer the question by telling them what you can do for this company specifically. In other words, while you want to mention some general skills that any company would desire (ie. strong communication skills, strong organizational skills, etc) you also want to mention specifically what you can do for this company. This means you need to understand exactly why the company is trying to fill the position you are interviewing for and then tell the interviewer specifically what skills and experience you have to address this need.
2. Make sure you fully address the main points contained in the job description and in particular the most important aspects of the description. Proactively refer to important aspects of the job description and discuss specifics related to your experience that illustrates your ability to handle these tasks.
3. In advance of the interview, look for any press releases, interviews or articles that discuss the direction of the company and their business. If possible during the interview, consider referring to what you read and try your best to relate how your experience and skills lend well to the direction of the company and their business. Not only does it illustrate that you've done your homework for the interview, it can also be a great way to make a specific reference to what you can do for the company that other candidates might not consider.
4. Remember to discuss relevant aspects of your background that could set you apart from other candidates for the job. If you hold a certification or specific training relevant to the position that others might not have, make sure you mention it. Don't make the mistake of assuming the interviewer knows it already even if it was contained in your resume.
All the answers you give and the questions you ask should focus on what you can do for the company and not on what they can do for you.
Asking how much money they'll pay you is a good example of a question not to ask. The issue of money will come up at some point and it's best to let the interviewer ask about it.