Such services are common around the rest of the country, but were never adopted in Manhattan. That has made it difficult for those hunting for an apartment, condo, co-op or townhouse to survey all the available properties without contacting a long list of brokers. Pam Liebman, CEO of Corcoran Group, headed by founder Barbara Corcoran, told GlobeSt.com that, "It's really a revolutionary change for the market because for the first time ever both consumers and brokers have a one-stop shopping opportunity. Until now it's been difficult for buyers to feel confident they're getting exposure to the whole market by working with one broker."

Why set up an MLS now? Liebman says that, for the last couple of years, brokers have been operating a de facto listing service, sharing a good portion of their listings with their colleagues. That arrangement was not very efficient, however, and so it was decided to formalize the process.

Reaction to the MLS has been positive across the board, she says. The firm has been contacted by "many, many" brokers, and it has gotten in touch with others. She does not think this new way of doing business will have any impact on housing prices or broker fees. Any broker is welcome to join the service, which is scheduled to debut early next year.