Eric Martin, 28, has tried his hand at day trading, running for Congress, and designing kids' games. None of those efforts came to much.

But his latest scheme could soon make him an Internet multimillionaire.

The fresh-faced father of two won a competition to recruit the most new users for the soon-to-be-launched shopping site Jet.com, the brainchild of a Web entrepreneur whose last business was bought by Amazon for about $545 million.

Martin was awarded stock options that could be worth $18 million if the company is successful, an outcome that some of the world's biggest investors are banking on.

"I still have my full-time job. This was more like a moonshot," Martin said recently in his small York, Pa., home. "I went for it and I won."

The contest netted Jet more than 350,000 sign-ups before it fully launches, about 8,000 of which came from Martin.

While other contestants used their blogs or social-media heft to drum up business for Jet, Martin paid for space on so-called rewarded advertising sites, where visitors absorb marketing messages in exchange for points that can be applied to gift cards.

His strategy, which blindsided Jet itself, exposed the fault lines between the Internet of high-profile bloggers and LinkedIn "Influencers" and the one inhabited by deal-seekers who spend time on rewarded advertising sites.

"The people who are the bloggers and influencers are not the kind of people who hang out on those sites," said e-commerce expert Steve Tadelis, professor at UC Berkeley's Haas School of Business. Martin "just put one and one together and did it."

Martin is a tall, lanky guy whose aw-shucks manner and enthusiasm for hamburgers and classic Nintendo games recalls Andy Dwyer, the lovable slacker on NBC's Parks and Recreation.

The Jet contest was the latest - and most successful - in a line of get-rich-quick schemes that Martin has pursued. In college, he borrowed about $15,000 from his dad to make a day-trading bet on a tech company, but pulled out before the stock did much.

Years later, he designed a kids' card game using photos of clay animals sculpted by his wife. But he stopped shopping "Animal Herders" around after its limited potential was clear.

"I have had some crazy schemes in the past," he said. "I have a box of [ideas], probably hundreds."

Martin got his current sales-support job at a funeral insurance broker through a family connection. An early assignment was to market a service that transports customers' remains home for burial if they die out of town.

Before that, he had worked as a Honda salesman and sold phones for a Verizon licensee. He even ran for Congress in 2012. A self-proclaimed Ron Paul acolyte who favors the abolition of the U.S. Education and Agriculture Departments, Martin came in fifth of seven candidates for the GOP nomination in his right-leaning district.

Martin first encountered Jet in a magazine story about the firm and its founder, Marc Lore, whose company Quidsi - home to Diapers.com - was acquired by Amazon after what has been described as a bruising pricing war. Lore went to work for the Seattle-based giant but left after about two years.

With Jet, he appeared to be setting himself up for a rematch with Amazon, offering customers access to discounted merchandise in exchange for a $50 membership fee.

The company, which has since announced funding by the likes of Bain Capital Ventures, Goldman Sachs, and Google Ventures, was in the midst of a prelaunch membership drive, offering 100,000 stock options to whomever could collect the most sign-ups, with the next nine top recruiters each getting 10,000 options.

Martin began persuading people around him to join, seeing his ranking rise dramatically with each new user. "I just kind of called some family and friends, and it really spiraled from there," he said.

By the time Martin joined the competition in earnest, just a few weeks remained before the winners were to be ranked. Contenders included a personal-finance blogger who had been quoted on Oprah.com (and who ultimately came in second), and a social-media marketer with a massive LinkedIn presence (sixth place).

Into this field strode Martin. His winning strategy emerged when he remembered Swagbucks and GiftHulk, the sites where his sister-in-law earned gift cards by signing up for mailing lists or answering surveys. Martin began placing listings on those sites, "essentially paying people to sign up," he said, eventually spending $18,000 there and elsewhere to promote Jet.

His intuition was that the sites and Jet would have an overlapping user base: young, tech-savvy moms like his sister-in-law with time on their hands and an appetite for bargains. The hunch paid off late last month when Jet announced its list of winners, with him at the top.

"I've been watching Eric come up with these wild ideas for so long," said his wife, Melody. "I've always known that one of them was going to work."

Sumaiya Balbale, Jet's vice president for marketing, declined to discuss the stock options' value, though Lore has blogged that the winner would receive "the same amount we've given out to some of our earliest, high-level employees." A 3 percent stake in the company, which Berkeley's Tadelis said would be on the high end for an early officer at a start-up like Jet, could thus be worth $18 million under the company's $600 million valuation reported last month by the Wall Street Journal.

Martin, who received an e-mail from Jet promising that the options are his, expects to receive official papers in April. If the company fails or remains privately held, the options would be worthless, though Martin believes his windfall will arrive.

Martin's success came as a surprise, Balbale said, since executives anticipated someone with a large social-media following would take the top spot and hadn't considered the rewarded advertising sites.

"It definitely defied our expectations," she said.