There is no official soft drink of the Brooklyn Bridge. The surface of Lady Liberty’s crown is not brought to you by a cellphone provider. And even the New York Yankees, corporate behemoths of America’s favorite pastime, have refused to sully at least one piece of real estate at their new ballpark — the name at the top of it.

But on Wednesday, New Yorkers learned that one of New York City’s emblems is not immune from the siren song of advertising dollars.

For the first time, the Metropolitan Transportation Authority announced that it would offer advertising space on the front of its MetroCards.

“Millions of New Yorkers carry MetroCards with them everywhere they go and use them multiple times a day,” said Joseph J. Lhota, the authority’s chairman. “For those with a message and a desire to reach millions of people in a novel, attention-getting way, there is no better way to advertise.”