The short answer is that it is an aspirational question, but if done right, can help potentially spot a great employee from the good.
From the perspective of an employer (or a team that is hiring) –
Having the technical competence for the job is a given. However, speaking specifically for fast moving industries like the tech industry, skills required on the job change fast. If you are not motivated to keep up and update your skills, you can soon be irrelevant.
That brings me to the key point which is motivation. I view motivation as being comprised of two sources. – intrinsic and extrinsic.
Intrinsic motivation is your internal drive to commit to doing something – be it completing a project at work, learning how to drive, learning how to surf, etc. For many, the drive to get up and go to work everyday can be as mundane as ‘a way to put bread on the table and a roof over your head’. But that’s not really motivation. This is enough to achieve the bare minimum – which is to do enough to keep your boss satisfied and ensure that you don’t get fired from your job. But it does not drive you to excel at your job or go over and above to help your company succeed.
As the hiring team, we are optimists/idealists at and don’t want just the bare minimum. We want to do better. So, we want people who are passionate about doing what they do. How does this show in the candidate? One way is to measure skill. Skills actually compound over the long term. If you look at two people over a period of time – one who did just what was required of his job but, did a good job of it, vs. another who constantly seeks to challenge himself at work and push the envelope, in 3 years, the gap between the two employees will be big. In 10, its not even a contest as to who the winner is. We want to identify and hire the later.
But this is still not enough. As a highly skilled employee, you probably have a mercenary attitude. Meaning, you will work for the hottest/coolest company or the company that has the best tech/product or the highest paymaster. Which means that your own motivation and goals only align with that of the company in so far as it suits your needs. You may be great at what you do, but the company cannot get the most out of you or maintain your loyalty for long if you are a mercenary. Highly skilled workers are prone to this, especially in a job market where demand for talent out strips supply. They may even get away with it successfully for a while.
Extrinsic motivation is a different view that is bigger than yourself. Your desire to be part of a larger story or organization that impacts some aspect of the customers’ lives in some big way. You may get cynical at this point and say that very few companies actually do something meaningful. I beg to differ. The scale of the people you affect (as in tens or hundreds vs. millions) may be different, but the impact on each individual customer may still be significant irrespective of scale. Ultimately, a customer will stick with you if you provide true value, otherwise you will not have him for long.
Now, once you become a part of this larger mission, you will be excited to get up and come to work everyday and tackle the challenges that come your way. Rather than questioning what this job can do for me, you will ask what I can do for the company in order to achieve its mission. In management jargon, this is called ‘alignment’. Lets face it, even the best technical jobs will frequently have some mundane work to get through. I get through those tasks by reminding myself that it matters for the larger purpose of the company.
So, in summary, this question helps the interviewer judge whether you are aligned to the larger mission of the company.
From the perspective of an interview candidate –
I have also been on the other side of this table. How does this question help me as an interview candidate? The short answer is to help me decide whether I want to work at a particular company or not.
Before I even seriously take up an interview, I learn as much as I can about the company. What does the company do? What problem is it trying to solve? What is the market for such a solution? How big is the team, and how important is the team’s function to the overall organization? Is the team’s existence crucial to the company achieving its mission? Is this a problem that I want to be a part of solving?
Thinking hard about these questions is really worth the time and effort. If after this point, I still want to work at this place, I probably know the answer to the question – ‘Why do you want to work for us.’
One way I like to think about the impact of a company is this – If this company or product didn’t exist, how would the customer’s life be different? Would he/she care, or miss the product and for how long?
For example: would you notice if Google didn’t exist today and you didn’t have Google Search or Google Maps? Would you notice if Qualcomm didn’t exist and you didn’t have super fast access to data on your mobile on the move? Would you notice if you didn’t have a computer or mobile to read this answer on? What if Quora didn’t exist, would your life be substantially different?
In the end, a team may still decide to hire a candidate if they don’t have a great answer to this question, because not all team members are expected to be extra-ordinary or superstars. But, the upshot of this is that if the candidate did have a great answer, it would be really obvious, and the likelihood of that employee staying on in the company to achieve great things for themselves and the company is way higher!
PS: As with all interview questions, this question is not without true positives or false negatives. For example, there are a good many engineers who would kill it at work, but may not be great communicators in sharing their view point with the interviewer even if they were incredibly motivated to the job and company’s vision. A good interviewer hopefully recognizes and compensates for that while using this question to make a judgement on whether to hire.