What are they trying to find out when they ask this?
Quite simply, what they're trying to find out is whether you know anyone who works for the company.
But I suspect you're more interested in why they would want to know this.
- Depending upon your relationship with someone who already works for the company, company rules may prohibit you from working in the same department/group.
- They may want to ask that person questions about you and how you are as an employee/colleague. Think of it as an internal reference check.
- If that person referred you to the company/position, they may be eligible for a referral bonus.
Pretty much what was asked. I don't think there's any manipulation or secret mind game with this one, but the company may have an incentive program for employees who bring on other employees that stay for a period of time.
An example: a few years ago, I had a brief stint at a market research firm. If I told a friend about it, the friend was hired, and the friend stayed on for 3 months, I'd get a bonus.
Another reason not touched on by the other answers but certainly valid is:
- to understand more about why they want to join
If they have some knowledge of the company culture and working practices and want to join then there is a better chance of them fitting in than a random stranger. Team fit and culture fit are very important concepts when hiring, as they increase retention considerably, and also tend to add positively to team morale.
Both of those provide measurable cost savings for most companies I have worked with, and are core team metrics where I currently am at a large multinational financial organisation.
Just to be careful: It is quite possible that you know someone working for the company (if you have been around in your industry for a while), without knowing where they work. So in order not to be suspected to be a liar, if you don't know of anyone working there I'd say "it's of course possible that someone who I know has joined your company, but I don't know about anyone" which is useful if they introduce you to a coworker that you haven't seen in ten years.