Big corporations can be unhappy places these days. The new president is very publicly smacking them down--about the cost of Air Force One, about drug prices, about the car plants they have in Mexico. Activist investors harangue Fortune 500 CEOs about boosting returns even as the bosses struggle to increase sales. If the big companies seem bereft of breakthrough ideas, perhaps it's because they are. Meanwhile, the Millennials they so crave as customers are hardly excited about working for them.

Fortunately for corporate America, where there has been zero job growth, where products are often out of touch, where mindsets are sclerotic, there is one force that could save them: entrepreneurship--or, more specifically, the entrepreneurs whose companies they buy. American giants have begun to recognize that the well of innovation is still gushing among the Inc. 5000. And they are thirsting for it.

There's a new, and favorable, twist in the tale for entrepreneurs, too. In the past, when a big company bought a small one, the founder got a big payday, but had to accept giving up control of a business built on years of love and grueling work, and that the acquirer, once in control, might have a slightly different plan for its new toy. Cultures clashed, cherished employees left, and all the excitement that went into creating the merger vanished. Even worse was the "acquihire," in which a company got taken out primarily for its talent--without even a pretense of synergy.

In the trend that's emerging, the founders of prominent startups are finding ways to sell their cake and have it, too. They can run their brands on their own terms inside larger corporations while at the same time providing spark and nimbleness to the parent company. "We needed some sort of outside catalyst to get our digital effort going at the speed I wanted it to," says John Schlifske, CEO of Northwestern Mutual, which bought fintech startup LearnVest. "I didn't feel we had the right speed and agility."

We're now at the point when entre­preneurship doesn't have to end with a purchase. Even better, entrepreneurs like Alexa von Tobel at LearnVest and Marla Malcolm Beck at Bluemercury get to operate with resources they couldn't imagine having as startups. Whether it's Northwestern Mutual jump-starting its online financial planning, or Under Armour building a connected fitness initiative with a startup such as MyFitnessPal, this is how the smart 21st-century acquisition gets done. "At some point, established companies have to adopt some startup thinking," says Alexander Chernev, a professor of marketing at the Kellogg School of Management. "It's not that startup thinking is the best thing ever. But it forces you to look at the world as a changing place."

"When we looked at the whole landscape, Macy's was so strong in their core retail and omnichannel capabilities," says Beck. That might not seem obvious, given that last summer Macy's announced that it would close about 100 stores and lay off 10,000 people. The shift to online shopping has forced Macy's, like many other retailers, to restructure. But Beck was confident, as she is now, that Macy's, one of the largest online retailers, could accelerate Blue­mercury's growth. With help from Macy's, for instance, Bluemercury updated and relaunched its website in nine months--far faster than it could have done on its own. Beck also points to the Macy's West Coast innovation lab, where the retailer is constantly experimenting with new technologies. Plus, she says, "they are an amazing team of operators. They're nice people, and they're incredible at execution."

The day the deal was announced, Beck did a call with her entire staff, who gave it decidedly mixed reviews. Employees worried about losing Bluemercury's family feel. The Bluemercury sales staff are year-round employees, and well aware that most department store makeup counters are staffed largely by part-timers and seasonal workers. But Lundgren had assured the Becks that Bluemercury would still be independent, as they wanted. "The idea was that they wanted to keep us running in our lane, and we could learn from each other," says Beck. By and large, the employees stayed. Their jobs and hours didn't change, and the Macy's benefits package was more generous than Bluemercury could have afforded on its own. While Macy's shrinks its footprint, Bluemercury is expanding quickly; it added 40 stores in 2016 and plans another 32 this year. That creates more opportunities to promote people.

Although she operates in a glam business, Beck has always been driven by data and numbers. As a high schooler, she did the books for her dad's real estate development business. "I remember searching for pennies to make things balance," she says. Before starting Bluemercury, she worked at McKinsey and then in private equity. She is still running the numbers on customers. If you shop at a Bluemercury in Chicago and then go to a store in New York City, that Big Apple store will know which products you've bought. When Bluemercury launches a product, that brand will often invite the store's top customers to try free samples, and track the amount those customers spend over time. Macy's is counting too. Says Lundgren, "If we could roll out 150 [Bluemercury] stores this year without jeopardizing the quality of the execution, I would do that."

As content as he is with Campbell, Grimmer always intended to start another company, and discussed his ideas with Morrison. Both are interested in the intersection of biology, food, and technology. Their joint interests led to Habit, which recently launched in the San Francisco Bay area. Founded and led by Grimmer, Habit delivers meals customized to individuals based on their unique biological makeup. (You think that might include a soup?) Grimmer envisions that Campbell Fresh, a division built on the Bolthouse Farms acquisition, will be instrumental in scaling the food side of the business. "We're putting three industries together in one company--food, biology, and technology," says Grimmer. "Having a strategic partner in the food space makes this infinitely more viable than if we were going to build it alone." Campbell is the sole investor in Habit, funding a $32 million A round. And yes, Campbell has an option to buy.

Entrepreneurs are good for two things: starting businesses and turning them around. As an entrepreneur, you learn never to take no for an answer, and a turnaround is similar. People tell you it's been done before and it's never going to work. It is the exact same no you hear as a startup. I've told all my team that there are easier jobs. The satisfaction needs to come from winning. And by the way, if we are successful, you will make money. Otherwise, you will not make money. When [SoftBank CEO] Masayoshi Son bought Sprint, he had already invested in Brightstar. He asked us to combine the procurement of Brightstar and Sprint. In less than eight weeks, we were able to save about $400 million. Because of that, Masa asked me to join Sprint's board. Brightstar was also serving Verizon, Apple, and T-Mobile. That started to cause a few problems in the industry. When the government called us and kindly let us know there was no way they would approve the merger of Sprint and T-Mobile, Masa pulled me aside and said hey, I want to make you CEO of Sprint.