Thanks to Tim Ferriss’s 4-Hour Workweek, most entrepreneurs are obsessed with the idea of outsourcing anything they can. Content creation? Outsource it. Product manufacturing and distribution? Outsource it as well.

The natural conclusion to this line of thinking is to outsource your inbound- and outbound-sales needs to an external team -- though, as anyone who has tried this process prematurely will tell you, generating a positive return on investment with an outsourced team isn’t as simple as signing a contract and bringing on new remote workers.

To learn more about how to use external sales teams effectively, I sat down with Steli Efti. Efti is a fascinating guy. He’s a Greek immigrant who bought a one-way plane ticket from Europe to Silicon Valley with a goal of launching a successful tech company.

It took him a few iterations, but eventually the software he’d built to run his own outsourced-sales business morphed into the software-as-a-service customer-relation-management and communications tool known as Close.io.

Related: 5 Tasks Entrepreneurs Are Better Off Outsourcing

Here are a few of the insights he shared based on his experience managing external sales workers and outsourcing his own company’s sales needs:

1. Don’t be the blind leading the blind.

One of the biggest mistakes Efti sees companies making as they try to outsource their sales needs is to undertake the process too early on. Essentially, they outsource sales because they don’t know how to do it well on their own, and they assume that external sales specialists can figure things out for them.

“Before you outsource your sales, you need to know the process and that it more or less works," he says. "You don’t have to have a perfect or fully documented process, but you do need to be able to verbally tell someone what to do.”

If you don’t know what makes your customers buy, it’s incredibly unlikely that somebody outside your company will be able to crack the code before you do. You don’t need to be a consumer-behavior expert, but you do need to be relatively familiar with how and why prospects become buyers.

2. Be hands-on.

Once you’re relatively comfortable with your company’s sales funnels, you’ll need to invest some time in training your external sales workers to make them truly effective.

Too many business owners see outsourcing as a one-time deal -- you sign a contract with a company, and then sit back while your new remote workers go full-steam ahead. Of course, we all know things rarely go that smoothly, but for some reason most business owners who consider outsourcing any business function still fail to account for the much-needed training process.

Instead, Efti encourages all companies to be as hands-on as possible during the onboarding process of external sales workers to the point of treating them the same way they’d treat new in-house team members. In his experience with Close.io predecessor Elastic Sales, Efti found that it was the companies that were engaged and hands-on about the process, as well as those that were able to step in and help fix problems immediately, that got the best results.

Related: 25 Businesses That Make Life Simpler for Other Businesses

3. Embrace the Pareto Principle.

To optimize this onboarding process and make external reps as effective as possible from day one, Efti recommends focusing training around “the 20 percent of knowledge that was needed 80 percent of the time.”

If you’ve ever spent any time working in sales, you know that you hear the same questions over and over again. So when you train your own sales workers, whether internal or external, why would you waste time detailing answers to questions that your reps might only hear once a year? Focus your training instead on the most commonly asked questions. Efti suggests that this usually won’t take up more than two pages with 10 to 20 questions total.

And if your sales reps encounter a question that isn’t on the list? Encourage them to get the answer from a more senior person (this is where being available comes in handy) and to understand the “why” behind the final response so that they can be more effective on their own in the future.

4. Invest in follow-up

Efti’s final application of the 80/20 rule comes in his obsession with proper follow-up. “In business,” he says, “follow-up is truly where winning happens.”

In his experience, too many people tell themselves stories about why their messages go unanswered, convincing themselves that people aren’t responding because they’re no longer interested. Following up creates the opportunity to reach prospects who were just busy, not uninterested, which can drive an 80 percent return on a comparatively small amount of effort.

For even more tips and tricks from Steli Efti, check out the full interview below:

Related: Your Company's Success Depends on Your Sales Skills