To attract new customers, it can be tempting to buy a trade show booth or launch a massive marketing campaign. And while these can be important for growing a big business, try to think of your side hustle as a “strategically slow start-up,” says Wilder. To keep your risk low and your profit margin high, spend only on items that are crucial for running your business, like a website or product supplies. Julia Baldwin and her husband, Richard Kotulski, had an idea for a late-night cookie delivery service in Portland, Oregon, but didn’t want to sink a lot of money into it. Once they found a great (and affordable) kitchen space, they decided to do a soft launch of After Dark Cookies. “We wanted to test the idea without requiring a lot of up-front capital,” says Kotulski. What they did invest in: ingredients and customer service. “It’s all about making the customer happy,” he adds.