As a kid, Northeastern University alumnus Casey Bertenthal made a few extra bucks by washing cars and walking dogs.

But his entrepreneurial spirit has truly blossomed since he joined a small startup a couple of months ago.

Bertenthal, SSH’10, is one of three full time employees of GroupBookers, an Oakland, Calif., based hotel booking web application that specializes in helping novice meeting planners, such as administrators or human resources managers, book event space or 10 or more hotel rooms.

The commission- based business launched its services in San Francisco and Los Angeles in late October and will be available to clients in Boston, Chicago, New York and Washington, D.C. by early next year.

The company, Bertenthal says, has a distinct advantage over competitors because of the site’s simplicity and ease of use for novice planners.

He describes the application as a hybrid version of Expedia and TripAdvisor for large groups. As he puts it, “There are no other sites out there that allow the user to enter their group needs and then narrow his or her search down to the 3 or 4 hotels that would best work for the group and then receive rate proposals from each within 24 hours.”

The entrepreneur manages GroupBookers’ social media strategy, including its Facebook, Twitter and LinkedIn accounts. Bertenthal also plays an active role in building prospective partnerships with hotels managers and meeting planners.

He relishes the day-to-day duties of shaping the low-risk, high-reward venture. “There is always something new and exciting happening,” he says. “It is a great opportunity to be part of something from its inception and grow along with the company.”

Bertenthal says his co-op in a marketing role with Joie de Vivre Hospitality, a hotel and restaurant company based in San Francisco, has prepared him to help turn GroupBookers into a widespread success.

“It gave me a knowledge base of the hospitality industry, from reservations to big group sales,” he explains. “I got a really good idea of how the industry works.”