Barefoot Books vs. Scholastic

The challenge: Finding the right way to sell children’s books.

What she did: Nancy Traversy isn’t afraid to challenge conventional wisdom. Her publishing house, Barefoot Books, known for beautifully illustrated children’s classics like Animal Boogie, pulled out of national store chains years ago because they made her eat large quantities of unsold books; she severed her relationship with Amazon this year out of frustration over its discounting of her products. Now the firm, based in Cambridge, Mass., sells via partnerships with companies like Lakeshore Learning and a network of home-based sellers called Ambassadors. “We’ve gone in the opposite direction of most publishers,” says Traversy, 52. The 21-year-old company, which she says is profitable, is making strides, projecting $7 million in revenue for 2013, up $1 million since last year. Meanwhile, it has marched into the digital age with its award-winning Barefoot World Atlas app for the iPhone and iPad, already downloaded 4 million times.

Twilio vs. Cisco

The Challenge: Taking on a global rival with its own Internet telephony solutions.

What they did: Jeff Lawson, 36, a former product manager at Amazon Web Services, couldn’t help noticing how many companies were gravitating to cloud-based technology. In 2008 he teamed up with techies Evan Cooke and John Wolthius to bring the convenience of cloud-based software to the telecom realm. San Francisco-based Twilio’s software makes it easy for app developers to embed high-quality phone-call technology into projects such as websites. Customers have new, cost-effective alternatives to offerings from Cisco, and they “don’t have to become a telecom expert,” says Lawson. Thanks to ease of use and clear connections, Twilio software is catching on fast. With 225 employees, it should bring in a reported $50 million this year. (Lawson won’t say if it’s profitable.) Venture capitalists are paying attention: Redpoint Ventures led a $70 million round in June.

Gigwalk vs. Crossmark

The Challenge: Getting companies to hire in-store help a different way.

What he did: Finding workers quickly for short-term tasks like restocking shelves can be a hassle for companies. Gigwalk CEO Bob Bahramipour, 43, formerly an exec on Yahoo’s search team, aims to speed things up with Gigwalk, which lets clients like consumer packaged goods company Reckitt Benckiser easily track down workers who use Gigwalk’s smartphone app. Bahramipour says the San Francisco firm, founded in 2010, uses extensive data on workers’ past performance to match them with gigs that play to their strengths, charging employers licensing fees and a percentage of workers’ earnings. “We end up deploying the chess pieces more efficiently,” he says. With $7.7 million in funding from backers such as Reid Hoffman’s Greylock Partners, he’s found plenty of takers and expects revenue of more than $4 million this year.

This story is from the November 18, 2013 issue of Fortune.