Interviews are not a good way to get to know a person. The process treats hiring like a romance, as if that had anything to do with the eventual marriage. I've found that human judgment is really bad in the romance phase of any relationship, because both sides are showing their best cards. What you really want to know is, What are the worst things about the person and about the company, and are those things going to work together?

We interview extensively, of course, but I think it's the third-best hiring tool.

No. 1 is actually simulating the job. During the recruiting process, we bring candidates in and have them do the job for a while. For our customer service Ninjas, we have them respond to customer email. For a VP candidate, I might bring him or her in to advise on a big decision: Here are the issues we're facing--now run a meeting where we figure out what to do. At the more senior level, I tell people, If we are going to hire you, we are going to spend about 40 hours of your time. That might sound crazy, but ideally we want this relationship to work for the next four or five years; that's 200 to 250 weeks. Why wouldn't we invest one week of time figuring it out? And by the way, if at the end you decide you don't want to do this, that's a great outcome.

No. 2 is off-list references. Everyone does on-list references, but that's such a checking-the-box exercise. It's like, talk to some handpicked people who will all say I'm great. It's hilarious--it should be a Saturday Night Live skit. In addition to talking to those people, you have to take the time to find other people who have worked with the candidate. And this is important: Try to get in touch with those people via your own network, because then they'll feel some accountability to you and will be more honest. For associates, we'll check one off-list reference. For managers, we'll check two. And for VPs and C-level executives, it's at least five. More often than not, we've gotten more excited about candidates because of their off-list references. In at least two cases I can think of, we pulled the plug on someone we were going to hire.

 As told to Inc. editor-at-large, Tom Foster.