This rumoured deal between Microsoft and News Corporation is all about attention.

Rupert Murdoch wants your attention on his news and advertising, and ideally for you to pay for it, too.

Meanwhile, Steve Ballmer wants your attention on your daily activities to happen via Microsoft’s services — especially Microsoft Office and Hotmail and Messenger and its Bing search engine, rather than Google Docs, Gmail, Google Talk and Google Search. Indeed, Office 2010 will work in a web browser, a clear response to Google Docs.

So if Microsoft pays Murdoch to remove his news websites from Google’s index and list them exclusively on Bing, how do they both benefit?

As entrepreneur Jason Calacanis speculated on November 9, Bing could differentiate itself on the basis of the exclusive content. “Want to search the New York Times, Wall Street Journal, USA Today and 3894 other newspapers and magazines? … Go to Bing.”

Bing would presumably get “free” promotion on News’ websites, too.

But from News Corp’s side, it looks like it’s purely about the cash.

Google currently sends News Corp’s US websites a significant portion of their total traffic, which costs Murdoch nothing. The Wall Street Journal, for example, gets 11.5% of its 12 million monthly visitors from Google. The New York Times, more than 17% of just under 18 million visitors.

Under the rumoured deal, that traffic and its associated advertising revenue would disappear. Could Bing replace it? Search engine analyst Danny Sullivan reckons that the WSJ would lose a million Google visitors a month while Bing would deliver just 150,000 in return.

“That’s about $180 million per year Bing needs to pay just to the WSJ alone,” he says.

Sullivan is also sceptical of Bing’s ability to promote itself as a trusted source. “People already think they’ve got that at Google. I don’t see it flying.”

Indeed, Gawker has published mock-ups showing what Google News would look like without Murdoch’s content. Not much different.

All that said, mUmBRELLA’s Tim Burrows wrote in The Australian that traffic from random drive-by Google hits isn’t of much long-term value.

“The locusts descended, devoured the story and moved right along. Very few stayed for a second page,” he wrote.

Other online publishers have confirmed to Crikey that steadily building an audience of repeat visitors is more important. Perhaps a longer-term relationship, with Bing News as the default in everyone’s web browser, is the true aim.

Or perhaps Murdoch is just sabre-rattling.

Bernstein Research analyst Jeffrey Lindsay reckons it’s all designed to put pressure on Google as it renegotiates the $900 million advertising deal with News-owned MySpace. According to Google Trends, MySpace has declined from 20 million unique daily visitors two years ago to well under 10 million today.

“We think Microsoft, as usual, is fishing in troubled waters in the hope that it may get something out of the situation or at least give [Google] a poke in the eye,” Lindsay wrote.