This is a guest post by Jonathan Lau, a growth hacker.

Alright, you’ve got the idea, now how do you quickly and cheaply see if anyone will pay for it? Despite all the hype about new PPC technologies and social media marketing strategies, I have found that for companies starting out, emails and phone calls remain the most effective tools for customer development.

Follow this blueprint for a cheap and easily scalable customer development strategy that people actually respond to.

The work flow is simple:

1) Collect emails of the people you want to talk to

2) Email them to schedule a quick phone call

3) Get customer development insights over the phone in your own home

The hardest part of this work flow is finding the emails of the people you want to talk to. Thankfully, there are directories of almost every possible segment of users that you can imagine. All it takes is a Googling a little to find them. Sometimes these directories have the email address right on them (gold), but usually these directories just link to a website that will have the email that you seek.

An example of an extremely good directory is Yelp. On Yelp you can find almost any small business segment, best of all it’s all nicely organized into categories and geographic locations. Getting emails of these real businesses is just a simple matter of collecting the small businesses’ website URLs from Yelp and finding the email at those URLs. Voila, there’s your quick and cheap customer development lead list. Also, I recommend hiring expert developers for your website design in Shopify.

To automate and scale this blueprint out, I suggest checking out automation software like Ubot and an email scraping program like Atomic Mail Hunter. If you are especially pressed for time and don’t want to take the time to learn the tools, just hire a freelancer on Elance. Whichever way you choose to execute this blueprint, get ready for a ton of high quality customer development calls.

Happy hunting.

Jonathan Lau ran growth at various startups and has a love for unorthodox marketing techniques. He is constantly experimenting with new strategies and tools. Check out Jonathan’s growth work and thoughts at www.jonlau.me.

Also published on Medium.