What are you doing with your spare time? A year ago, 30-year-old Eric Martin decided to spend his evenings after his 9-to-5 job to help startup founders he had never met with a new website that was yet to launch.

He got 100,000 shares for his efforts which – a year later – are worth over $20 million.

That’s because that new startup – jet.com – just sold to Walmart for $3.3 billion. Martin’s reaction? “It feels good. It feels really good. The way I think to describe it is ‘occasional hysterical laughing.’”

It was only last Feb 2015 that Eric stumbled on a launch that entrepreneur Marc Lore had put together for his new startup. Marc sold his previous company, Quidsi (which included sites like diaper.com and soap.com) to Amazon for $540 million in 2010, and he was ready for his next big thing – a new retail site to beat Amazon at their own game.

His new startup – jet.com – would find the lowest price across the Internet for any product. But how could he get a buzz going before the launch? Marc decided to run a competition for whoever could refer the most subscribers to a 6 month free trial for jet.com when it launched, with the winner getting 100,000 share options in the company.

That’s where Eric came in. Working at a funeral insurance company, Eric came across Marc’s story in his dad’s copy of Businessweek and got excited. “Challenging Amazon is an incredible feat to try,” he thought. “100,000 stock options in a company trying to do that is just really exciting to me.”

So he signed up for the competition 3 weeks before it was ending, and started inviting the few people he knew to join – starting with his wife, brother, sister and parents.

That’s when he noticed something odd… After his first referral his rank in the competition went up fast from 232,582 to 13,767. The second took him to 7,518, then the third to 5,232nd. Maybe he could work out how many referrals he would need to win?

So he used a 30 day free trial of a statistics app he downloaded to work it out, and figured he would need just 2,000 referrals to have a chance.

So what did he do? ”I was really thinking about it… I thought, ‘I think I can win. Should I win? Should I do this?’ I think I prayed about it a little… If it’s going to me or someone else, I thought, why not do it?”

So he did it.

Marc spent the next 3 weeks online after work trying everything to get referrals. He tried Facebook ads. That didn’t work. He thought of Google Adwords. But others were already trying that. Then his sister-in-law told him about sites like Swagbucks and Gifthulk that already attracted people looking for free rewards in return for doing surveys.

Eric explains, “One of their most important demographics is mothers. They’ll do a survey in exchange for a one-month trial of cosmetics.” This was his target market, and they were already “trained to sign up for things.”

So Eric took the plunge and paid Swagbucks $3,000 of his hard-earned salary for a campaign. Within a few days, he had 2,000 sign-ups and was in 7th place.

But there was a problem. He learned the first place in the competition had over 4,000 sign-ups and rising fast. So Eric decided to go all in, thinking “If this works out, it should be worth well more than my investment.”

He ended up spending $18,000 in campaigns, admitting “My wife was nervous.”

He ended up with 8,167 referrals and at midnight on Feb 5th 2015 he found out he had won, and went down to the grocery store to buy some crab legs to celebrate.

Today, just a year after jet.com’s site launched, it has been sold to Walmart for $3.3 billion and Eric’s 3 weeks of work, $18,000 in costs and 100,000 share options are worth an estimated $20 million+.

What Eric did is something anyone could have done if they had the same initiative, commitment and focus. He won it by deciding to win it – even though he didn’t know how.

What are you doing with your spare time? Who could you be helping? What could you be reading to find the right opportunities?

Your efforts may not, like Eric, take 3 weeks. It could be less. It could be more. And your results may not, like Eric, be $20 million+. It could be less. It could be more.

But for success today, it doesn’t take the best talent. It doesn’t take the greatest idea. It doesn’t take rare know-how.

It simply takes choosing to help, choosing who to help, a lot of action and a little luck.

On today’s news, Eric says ”I don’t think I’m some genius person that I thought Jet was going to work out. It was a gut instinct… I’m taking time to process it. I haven’t really had a chance to really feel what it means yet.”

“But I’m very, very happy.”