Except whatever Bill Gates's ambitions are, being William Randolph Hearst is not among them. When he and his staff realized that the cost and effort to go after well-established weeklies would be in the hundreds of millions of dollars, they quickly lost interest. Then they were jumped by city guides who were spending less money because they had established themselves in virgin markets. Sidewalk always acted as if their rivals were somehow lesser beings. The problem with a project like Sidewalk is that to go after newspaper classified ads, your site has to be a must-read.
People have to have a strong reason to go every day.
Without that, they won't go there. And If they don't, you don't make money. This is a viable project, if you spend enough money to support it. But you'd have to run it like a newspaper chain, not a weekly guide. Microsoft spent more money on these failed projects than many companies spend on developing complex networks.