It’s 11 p.m., and you’re in your local big-box store. You’ve got a package of white sports socks in each hand, and you’re trying to figure out which one to buy. One brand has your childhood sports hero smiling on the package, and the other comes highly recommended by your best friend.Which do you choose?Oddly enough, the same question torments marketing professionals as they try to figure out which approach will resonate with their target market: the highly personalized grassroots campaign or the good old-fashioned celebrity endorsement. And the answer isn’t easy.Which Approach Will Ignite Your Audience?Celebrity endorsements have long been embraced as the go-to marketing strategy for brands looking to establish trust and build excitement with new customers. But consumers have developed a distaste for in-your-face advertising tactics, and new studies suggest that grassroots advocate campaigns might have just as powerful an effect on customers as celebrity endorsements.There’s no single factor that determines whether a grassroots campaign or celebrity endorsement is best for your target audience. However, there are clues that can help you discover which option is best for you. Here are three considerations that can help you select the right approach:1. Analyze your budget for the best ROI. Don’t think that a small budget makes your decision easier; a budget of any size can secure a less obvious, but still powerful, celebrity influencer — regardless of whether it’s the best choice for your brand.What matters most, though, is that you choose an approach that will resonate with your audience for the most powerful ROI.Taco Bell’s “Burner Phone Breakfast” grassroots heist is a great example of using a minimal budget for maximum impact. After sending phones to 1,000 of its 1.1 million Twitter followers, the brand texted and called each phone with different challenges to complete, then rewarded these fans with Taco Bell prizes and gear.This effort created a lot of engagement and awareness via social media and targeted its Millennial audience perfectly — all at a fraction of the cost of contracting a popular celebrity.2. Track target audience conversations. You can’t confidently predict which trends will appeal to your audience unless you’re tracking their social media conversations in real time.Gather data and try to incorporate celebrities, events, or topics your audience mentions into your current marketing strategy. Listen to what your audience cares about (their friends’ opinions, a hot TV star’s endorsement, etc.), and redistribute that information in creative ways.Telemundo is a great example of a company in tune with its audience’s interests. In partnership with Latin World Entertainment, the TV channel invited 100 of its top social media influencers to come on screen and judge its new talent competition, “Yo Soy el Artista.” This approach strengthened the show’s relationship with its social media influencers, who, in turn, promoted the show and the experience to millions of followers. 3. Read into every audience detail. Go a step beyond tracking conversations to uncover your audience’s deeper motivations. Use a social media segmentation tool to identify unique characteristics that describe your audience and popular, but less obvious, influencers.Every trait you can uncover — from being eco-friendly to price-sensitive — is an important indicator of what will warrant a response from your audience. And if you’re going the celebrity route, this will uncover the people they really care about, not just the hot celebrities of the moment.Under Armour did a great job of incorporating its knowledge of its audience into its celebrity promotions with the current “I Will What I Want” campaign featuring Gisele Bündchen and Lindsey Vonn. By featuring real women celebrities who have overcome criticism, injuries, and more, each powerful promotion connected with the everyday athletic woman and created buzz around the brand.It’d be a lot easier if marketing campaigns came in a one-size-fits-all package, but that’s not how you make a genuine connection with your target consumer. Put in the work to determine what resonates with your audience, and use that information to develop an effective grassroots campaign or secure a compelling celebrity endorsement.