In business, getting eyeballs can often make the difference between becoming the next big thing or a total dud. The same is true for social ventures, save for one key factor: Celebrities will often chip in and help, gratis.

This year's Nexus Global Youth Summit, going on now through Saturday at the United Nations in New York City, convened a lively panel of Hollywood-power players: actor, social activist and co-founder of multi-media platform SHFT Adrian Grenier, Darnell Strom, an executive at talent agency Creative Artists Agency, SVP of corporate responsibility at global-media company VIACOM David Katz and Naomi Hirabayashi, the CMO of Do Something, a nonprofit organization focused on getting youth involved in cause campaigns. Among other things, they delved into the topic of how celebrities can help ignite social change.

If you use pop culture in the right way, it is a very powerful medium to reach millennials, a demographic estimated to be one-third of the world population, according to the panel.

While the discussion highlighted nonprofits like charity: water doing an excellent job of integrating talent into their message, they did acknowledge not everyone knows how to engage celebrities or the first steps social entrepreneurs should take.

Related: The Power of Giving Back: How Community Involvement Can Boost Your Bottom Line

How to Get Entourage's Adrian Grenier to Tout Your Social Venture? Give Him Something to Believe in
A panel of Hollywood heavyweights talks about how social entrepreneurs can leverage celebrity power for change. From left to right: Adrian Grenier, David Katz, Naomi Hirabayashi and Darnell Strom.

If you are looking to team up with a star for your social endeavor, here are five secrets on how to get them on board:

1. Start out small.
Don't be intimidated by the big guns in the industry. It is okay to start your social endeavor small and grow slowly, as Greiner explained. By doing so, you make fruitful connections and develop a business model that works, which helps bolster your chance of teaming up with famous folks and ensuring goals are aligned.

2. Know your audience.
Katz touched on this matter when he discussed how across VIACOM's assets -- from VH1 to Nickelodeon to BET -- what resonates with one demographic, won't necessarily jibe with another. Before you target your celeb wish list, make sure you know who would appeal to your core audience. Why go through all the work of getting a celeb committed to your venture when it could provide little response, or possible backlash?

3. Make sure your partnership passes the smell test.
People aren't dumb, and they can smell BS from a mile away. They can tell when celebrities are on board just for publicity sake and when they really care about the cause.

Related: How to Launch an Ethical Brand After the Rana Plaza Tragedy

When forming a partnership, make sure the star has a strong desire to collaborate with you. People don't want to see anything scripted or fake -- they want to see real dedication and compassion for the initiative.

To this point, Grenier added that he couldn't do everything. Instead of spreading himself thin, he limits his focus on root issues, like water and the environment, to be the most effective and provide the biggest potential for positive change.

4. Stand out in the crowd.
To get past a celeb's gatekeepers -- publicists, organizations and social connectors -- have a compelling story. Do you have images of a well you are digging in Nairobi or a tale about visiting families in rural areas? If so, let people know. With social entrepreneurship being a crowded space, it's imperative to stand out.

Related: How Two Recent Grads Turned a Study Abroad Trip into a Social Venture

And just like any business, oftentimes connections have to do with the bottom line. If your plan of attack requires celebs to jump through expensive hoops to get the partnership up-and-running, the likelihood it will occur is close to zero. "You need to be first, fastest, only or the cheapest," says Hirabayashi.

5. Celebrities are people too.
"Below this shell of a celebrity, there is still a man," says Grenier referring to himself.

Celebrities function the same way as everyone else. So, treat them that way. If you are just vying for a star to walk the red carpet, snap pics and pose next to your signage, it's not going to work. Ensure the partnership is mutually beneficial and is meaningful to the celebrity.

One great way to do this is to invite the famous person to an event where there is no press and no expectation, says Hirabayashi. By doing so, you can suss out if there is a connection and if the partnership would be a good fit.

How would you get a celeb's attention? Let us know in the comments.