Care.com founder Sheila Lirio Marcelo got the idea for an online marketplace for care providers after she struggled to find qualified professionals to take care of her aging parents. Today, consumers can search on Care.com for child, senior, pet, and home care services, while providers can create profiles and search for jobs. The company pledges to keep customers safe by giving them the option of requesting a background check on any care provider they wish to hire. Though its services are popular--Care.com currently has more than 10 million members--it has struggled to become profitable. But the company believes that its growing international business, particularly its Berlin-based subsidiary, Care.com Europe GmbH, will help it keep its competitive edge. Note: employee count as of Dec. 31, 2015

A picture might be worth a thousand words, but wearable-camera maker GoPro wants to ensure those stories get told. That's why, after a bumpy year, CEO Nick Woodman is emphasizing software. His San Mateo, California, company has recently introduced or improved several products to help customers edit videos on the fly, store them in the cloud, and, of course, make them in the first place. "GoPro got started in the packaging," says IFI analyst Larry Cady. "But now they've started patenting around more of the electronics, like image processing and network communications." --Victoria Finkle

Steven Price and Stuart Rosenstein founded media and entertainment company Townsquare Media in 2009. Today, Townsquare owns more than 625 local radio stations and websites, and operates more than 500 live events each year. The company has pursued many acquisitions over the years as a means to increase its reach--most notably, it purchased a number of websites from AOL in 2013. Many of Townsquare's media properties target audiences in small to midsize markets, which the company says are traditionally less volatile than crowded national markets. But Townsquare depends heavily on advertisers to help the company generate revenue--and any economic downturns in the markets that Townsquare serves could mean advertisers spending less money on Townsquare properties. Townsquare hopes to diversify its revenue mix in the coming years by increasing its portfolio of live events and rolling out new digital products. Note: employee count as of Dec. 31, 2015

Marketo, founded by Philip Fernandez, sells software that companies can use to consolidate their online, social, and mobile marketing activities into one platform. To stand out from other software marketing companies, Marketo touts its customer-service tools, which include consulting services and discussion forums for Marketo customers. The company says its goal is to help customers navigate the evolving digital market landscape. Marketo faces stiff competition, however, from large, enterprise-level software companies that are now getting into the marketing software game, including Oracle and SAP. To stay innovative (and to continue meeting the changing needs of its customers), Marketo says it plans to release a new application for its marketing platform every 12 to 18 months for the foreseeable future. Note: employee count as of Dec. 31, 2015

Spun out of Stanford University, business analytics company Tableau Software was founded by Christian Chabot, Chris Stolte, and Pat Hanrahan. The three co-founders also played a hand in the invention of a data-visualization language called VizQL, implemented in Tableau's original software. The company aims to help businesses see and understand their data better, selling software that turns data points into visual presentations. Tableau's history of profitability has been spotty--it turned a profit in 2013 and 2014, and then lost money in 2015--so it is unclear how successful the company will be in the future. But Tableau feels that it is well positioned, since the business-analytics-software industry is still relatively new. Note: employee count as of Dec. 31, 2015