Sure you have to gamble, but the only way this will make money for Murdoch is if makes less money on people who comes to his site from a search than it costs to serve that page; unless he has gotten the worst bandwidth-deal of the century.
If Newscorp has 10 million visitors per time period, and makes a net of $0.01 per visitor, that's better than nothing, but if they can go down to 1 million visitors per time and net $0.15 per visitor, it's better. Murdoch seems to think that they can do the latter. I don't have any data to refute him, and neither, I'd guess, does anyone else in this thread.
It's possible that Murdoch is totally off his rocker, but it's usually a fair baseline strategy to assume that the guy who runs a multi-billion dollar company has a bit of business acumen.