Recently, I posted an ad for a product-designer position at Basecamp. Product designers lead the visual design of individual projects. They also lead the process of figuring out what we should be working on. We don't hire often, so it's a unique opportunity for someone--and for us as a company.

For this position, I'm on the lookout for the usual set of design skills: clear thinking and communication, great taste, the vision to connect disparate ideas, and the ability not just to dream up new projects but also to implement them. But there's something else I look for before all that. This quality has never let me down. When I see it in someone, the person shoots to the top of the candidate list. And when I don't see it, off the list the person goes.

It's effort. I hire people on the basis of the effort they put into getting the job. We don't define effort; we just ask for it. It's up to individuals to decide what it means and demonstrate it in their own way. The latest ad for a designer says simply, "Send relevant work samples, and anything else that will make you stand out, to jason@basecamp.com. Extra effort and personal touches will be looked upon favorably."

Unfortunately, effort is rare. Out of the nearly 200 applications we've received so far for this position, only about 10 percent show a level of effort that gets our attention. What does effort look like when someone's applying for a job? Let's start with what it doesn't look like: sending in a standard résumé and cover letter or, worse, just a link to LinkedIn. Compare that with the candidate who sent a link to a custom-designed website that's all about getting this particular job. People who really want it don't toss their whole portfolio at me; they pick relevant examples and explain the thinking behind them. They don't speak in generalities about what makes them great; they speak specifically about how they would be a great addition to Basecamp.

As more and more people battle for jobs, making more of an effort than everyone else is a great way to stand out. It says so much about that person's work ethic and ability to sell his or her ideas. If someone isn't going to demonstrate those things to get the job, why would I think the person would show them after being hired?

Effort also tends to create unique opportunities. In fact, I met my business partner, David Heinemeier Hansson, because he put in more effort than anyone else. Back in 2001, David was a student at Copenhagen Business School. He didn't have a résumé, and he didn't have a lot of experience. But he went out of his way to help me with something, and that spoke much louder than anything else he could have done.

Back then, I was learning how to program in PHP, and I posted a message on our blog saying I was stuck on something that I just couldn't figure out. A bunch of people wrote in, but David's response was thoughtful, complete, and easy to follow. We traded a flurry of emails, and his responses were equally helpful. He wasn't even applying for a job, but he made a huge impression on me. Ultimately, I hired David on a contract basis to do some programming. When he graduated, I hired him full time, and eventually he became my business partner. It all started because I asked for a little help and he gave back a lot.

Never underestimate the power of extra effort. It's not taught in school. It's not mentioned on resumes. But it's the one thing a candidate can offer to really stand out--and a powerful thing employers can look for to identify a great hire. Make it your own little secret weapon.