How do you keep investors beaming if your two-year-old nationwide pay radio service is deep in the red and trailing its rival in the user race? By focusing on the big picture, of course.

Sirius

(SIRI) - Get Report

Chairman Joe Clayton is doing just that. He opened his remarks at the Credit Suisse First Boston Media and Telecom Week investment conference in New York on Monday with a list of markets that satellite radio can address. He started with cars, trucks, boats and recreational vehicles before going on to add homes, stores and offices.

In total, that's 350 million potential satellite radio sales opportunities, by Clayton's count.

For the time being, though, the New York pay radio shop is resigned to hitting the million-subscriber mark by year-end. Clayton reaffirmed Monday that Sirius intends to hit that target, thanks to hearty holiday sales. The company had about 800,000 users when it offered investors an update last month.

In terms of visibility, if not financial measures, Sirius has now eclipsed Washington-based premium radio peer

XM

(XMSR)

, which has more than 2.5 million users. Indeed, Sirius has catapulted itself into the big media circles this fall by signing Howard Stern and hiring former

Viacom

(VIA) - Get Report

President Mel Karmazin as CEO.

But now with big-salary talent joining manufacturing and marketing costs on the profit-and-loss statement, some investors are increasingly interested in learning when the rising tide of red ink might finally turn. One investor at the conference went so far as to ask how many subscribers Sirius would need to break even.

CFO Dave Frear replied that the company doesn't publicize break-even projections. Frear added that Sirius expects to burn or use $450 million in cash this year. That's slightly higher than the $430 million projected in July. But Frear says that the company has $800 million in cash on hand and that that should be plenty for the near future.

When asked in a side discussion after his presentation about the advertising revenue that he hopes to get from the Howard Stern shows, Clayton again pointed to the big opportunity. He said Infinity, the current holder of the Howard Stern contract, books between $80 million and $90 million a year. "We'd be happy with a sniff of that to get started," said Clayton.

But value-oriented investors like Marcelo Szekacs de Magalhaes with Investidor Profissional say the Sirius story relies on a lot of speculation.

For example, for Sirius to claim a potential market of 350 million subscribers implies that a lot of people in the U.S. will have two satellite radio subscriptions, he says. Yet Magalhaes doesn't see how that adds up.

"The radios are portable, so I don't see why they think people will buy two," says Magalhaes, who holds no Sirius stock. "I think they might be exaggerating the market."

Sirius shares, which have now doubled in the past month, rose 54 cents Monday to $8.09.