When Shaun Neff launched Neff Headwear a decade ago, he knew his streetwear line could get a big boost if he could find some high-profile fans. But as a start-up, he lacked the cash needed to pay celebrities to endorse his products.  So he reached out instead to users who'd have street (or ski slope) cred, giving away Neff beanies and headbands to amateur snowboarders.

The brand took off, eventually picking up genuine organic interest from celebrities like Lil Wayne. And as the company expanded beyond the “surf, skate, and snow” niche, Neff was able to start paying celebs to wear his wares.  While he still gives away merchandise to up-and-coming influencers, he has also paid recognizable athletes to wear Neff gear and secured profit-sharing endorsement deals from the likes of hip-hop legend Snoop Dogg.

The payoff: a revenue increase of more than 300% during the past three years, Neff says.

For a start-up trying to make a splash, endorsement deals usually come at too high a price. Here are four other ways that companies that have scored high-profile endorsements in unconventional ways.

Offer Equity

Barc, a line of male skincare products, reached a deal with star NFL running back Reggie Bush this March in which he agreed to be the face of the brand for an undisclosed stake in the company.

Such deals can help companies land a high-profile endorsement while saving money--and giving the the endorser an incentive to keep promoting the products.

 “When you’re a small business owner, cash is king. You want to preserve as much cash as possible,” said Chris Hayes, Barc founder and CEO.

“In order to preserve cash we thought it would make the most sense for (Bush) to come in as an equity partner and use that money to help roll out new products, spend it on marketing, research, and packaging.”

Hayes began Barc as a high-end line specifically designed for African-American males. He is hoping to use Bush’s cross-cultural appeal—and more than 2.3 million Twitter followers—to expand the brand to all men, and eventually to women.

Hayes said there are plans for Barc to launch a female skincare line, and that Bush’s popularity with both genders was a major factor in seeking his endorsement.

Get a Cause

With some celebrities looking to burnish their reputations by being associated with charities or nonprofits, small companies can use cause marketing to find common ground with a potential endorser.

Australian entrepreneur Chris Clarke launched energy shot product Street King with Curtis “50 Cent” Jackson in September 2011. Using the business model popularized by TOMS Shoes, Street King has a partnership with the World Food Programme that feeds a hungry child for every shot purchased.

So far, the company says it has sold 3.5 million Street King units (and, the WFP confirms, has provided 3.5 million meals). Now Clarke says Street King is poised to become the second-highest grossing brand in the $1 billion industry.

Redefine Celebrity

Sometimes, fame depends on context: An endorsement from a high-profile Twitter personality might have as much pull as a photo in Us Weekly. And StyleCaster founder and CEO Ari Goldberg has been working to capitalize on these social media “non-celebrities.”

Recently, StyleCaster released the 2012 version of its annual 50 Most Stylish New Yorkers list. With a few exceptions—including Knicks forward Carmelo Anthony and “Boardwalk Empire” actor Vincent Piazza—Goldberg’s list was almost exclusively comprised of “influencers,” or what he calls “micro-endorsers”: people whose Internet followings engage a large consumer base around a specific topic.

Goldberg then uses the StyleCaster list to fuel marketing campaigns for major brands. For example, when Bloomingdale’s tapped Stylecaster in March to market its new denim collection, Goldberg selected five influential fashion bloggers from his network to style the new collection (and market it to their loyal readers).

 “I think the idea of celebrity is very interesting,” said Goldberg. “Who are we to decide what celebrity is?”

 Get Lucky

Sometimes it’s better to be lucky than good. But in order to create a successful business, the entrepreneurs behind fashion brand Rebecca Minkoff needed to be both.

In 2001, Uri Minkoff and his wife were at a party in Los Angeles. His wife was wearing a T-shirt made by Uri’s sister, Rebecca—a fashionable take on the ubiquitous “I Love NY” logo. At the party, Jenna Elfman—then starring in the hit television show “Dharma & Greg”—noticed the top and asked for one like it.

Elfman received her shirt on September 9, 2001, and then wore the shirt during a Tonight Show appearance on September 13, two days after the 9/11 attacks. Jay Leno asked Elfman where she received the shirt—and her answer made Rebecca Minkoff's phone start ringing off the hook.

after three years of making shirts on the floor of her apartment, Minkoff was burned out. So her brother gave her the capital to turn the brand into a "real" company, stepping in as CEO of Rebecca Minkoff LLC. Today the brand gets organic endorsements from celebrities like Reese Witherspoon, Minkoff says--and brings in more than $35 million in annual revenue.