To the disappointment of some and the jubilation of others, the traditional model of rental brokerage is increasingly endangered, its practitioners set scurrying in the manner of Ice Age scavengers. With the rise of websites the ones like Trulia and Streeteasy, which was founded in 2005 and is by far the dominant operator in New York City, listing information has never been more directly accessible to end users. The position of rental brokers, who once guarded their secrets like priests before the era of Martin Luther, has grown precarious. And those thriving in the present era have largely adopted strategies bearing little semblance to those that prevailed in the past.