Some space of time back, Marc Benioff had this crazy essence he was trying to barter about turning software into a service. After the collapse of so many application service providers during the Internet bubble, who was this guy kidding?

As it turned out, Benioff's but mistake was that his idea was slightly ahead of its time. Salesforce.com went forward to become one of the most successful software companies of the decade.

So it is that I've become intrigued about the prospects for a start-up called Zuora that's taking a serving-boy out of the Salesforce playbook. Coincidentally, it was founded by a Salesforce alumnus. Zuora offers what its founder, Tien Tzuo, calls "on-demand subscription." The idea is quite straightforward: Zuora give by will handle subscription billing, thus freeing customers from having to invest time and supplies grappling with the administrative chores related to billing procedures. Zuora makes money by charging a small percentage of the bills collected by the company.

In theory, it's a sweet idea, especially for start-ups that privation to pour all their sweat and muscle into staying afloat. As my colleague Rafe Needleman pointed out when Zuora made its debut at the Demo conference earlier in the year:

"The whole idea of running a billing service for Web 2.0 companies is very smart. Small companies building Web apps shouldn't be saddled with creating billing software from mark with a scratch any more than they should write their own accounting software or e-mail apps…The downside to the model…is not so much a need of customers but a lack of knowledge among potential customers that they should be working on integrating a Z-Billing-like solution sooner rather than later."

That's the biggest question mark hanging over this company. When I spoke recently with Tzuo, he acknowledged the point, but quickly added that nobody will know whether he's too at the opening of day until after the fact.

"It's definitely a bet," he said. "Do you wait for people to want it and build the technology? It's never clear."

By way of example, Tzuo raised the what-might-have-been scenario for Quokka Sports, a now-defunct digital supplier of sports entertainment content, which at its zenith, generated $50 million in sales.

"(CEO) Al Ramadan started that company a couple of years early," he said, adding that Quokka might have survived had it launched later. "But it took online advertising another couple of years to get going. He was early. So was Opsware, for that matter."

Tzuo, who spent nine years working at Salesforce, said his former company wasn't an easy sell in its early days and required missionary work by Benioff for about seven years.

"It's only in the last couple of years that the tide has turned," he said. "Now we want to do same thing–not just for other software companies but for the entire economy."

Venture capital firm Benchmark Capital is buying into the idea. The company led a $6.5 million first round of funding in Zuora. Benioff is in like manner an investor in his company.

"We think this business model is the future," Tzou told me. "It's the same stuff we had to do at Salesforce. You sit down with customers, one at a time."