Why this man spent $18,000 for 100,000 shares of stock in a company that hasn't even launched yet

Jet.com, a startup that wants to compete with Amazon, raised $140 million at about a $600 million valuation in February. Before that it raised $80 million.

The site, which will use a dynamic pricing model to sell products as cheaply as possible, hasn't launched yet, but the company has recruited 350,000 people to join in March, thanks to its "Jet Insiders" program.

Jet Insiders was an unusual referral contest.

Anyone who signed up got a unique link to share with other users. The ten people with the most referrals got 10,000 shares and the number one referrer got 100,000 shares of stock. That's the same amount Jet has given some of its earliest high-level employees.

Today, the company released its list of winners, and the top Insider, Eric Martin, told Business Insider that he spent about $18,000 on Facebook ads and rewarded advertising on Swagbucks.com and GiftHulk.com to ensure that he'd get the 100,000 shares. (Swagbucks and GiftHulk give people rewards for completing surveys or, in this case, signing up for websites.)

"Challenging Amazon is an incredible feat to try," Martin says. "100,000 stock options in a company trying to do that is just really exciting to me."

Martin heard about the company's mission and the Jet Insiders program after reading a a profile of founder Marc Lore in Businessweek. Like Amazon, the site will sell just about everything - but it promises its prices will ultimately be 10 to 15% lower than they are anywhere else. In exchange, people will pay a $50 annual membership fee. It's like Costco, but online.

Martin knew how obsessed people are with Costo, and how well the membership model works, so he started trying to figure out what he would have to do to win the contest.

"I could have spent much less money to just get into the top ten," he says. "But I realized that being the winner, with 10 times more stock, was within my grasp."

Martin, an ancillary product specialist at a pre-need funeral insurance company in Pennslyvania got over 8,000 referrals, cinching him the top spot. He'll be able to vest or exercise his stock options if Jet ever goes public or sells to another company. If the company completely flops, his $18,000 investment for the stock will be worthless.

"I feel like I'm kind of linked to the success of the company now," he says. "If it doesn't work out, I'll be disappointed. But I also looked at this contest as an opportunity to show my marketing skills and ability to come up with unique solutions to problems. It's a cool story, and I'm hoping it will be worth it."

If the Jet stock options do pan out big-time, Martin says he'd likely start a company of his own. He's interested in the concept of crowdfunding ideas.

All Jet Insiders will also get a six-month free membership to the site. The Top 1000 Insiders will receive a free five-year membership, and the top 100 earned a lifetime membership.

Here's the complete list of all the winners who will get stock:

1. Eric Martin of York, PA
2. Kyle Taylor of Saint Petersburg, FL
3. Collin Morgan of Boise, ID
4. Andrew Reid of Tampa, FL
5. Kevin Schlenker of Tampa, FL
6. Dave Kerpen of Port Washington, NY
7. James Seijas of Short Hills, NJ
8. Ken Irwin of Hatboro, PA
9. Steve Bowers of Charleston, WV
10. Bogdan Semida of Maplewood, NJ

Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.