It is always a risky strategy for any entrepreneur to bill their business as the next big thing in their market. And it is all the more risky when the comparison is a business as successful as Salesforce.com, the $14bn-plus online customer relationship management company.

But this does not deter Tien Tzuo, founder and CEO of Zuora. Perhaps because he was one of the people behind Salesforce's success (he was employee number 11, and ended up chief strategy officer) or perhaps because Salesforce CEO Marc Benioff is a personal investor, Tzuo believes he can justify the comparison.

There is a long way to go, of course. When CNBC Business met Tzuo, Zuora was poised to announce a $36m fundraising, led by Index Ventures and including a further subscription by Benioff. This fourth round of investment values it at $300m, and much of the new money is earmarked for expansion in Europe.

According to Tzuo, a push into Europe is long overdue. Zuora was founded in Silicon Valley in 2008, but only recently set up a permanent presence in EMEA, with London as its base. This is despite customers such as Dutch publisher VNU Media, News International and Touring Club Suisse using its services.

As Zuora, like Salesforce.com, operates over the internet as a 'software as a service' (SaaS) or cloud-computing company, it started to attract overseas interest long before it had a physical presence outside the US. Customers could simply sign up to use Zuora - which provides billing and related services - online. Already, Zuora handles subscriptions worth €2bn a year for its European customers.

"At Salesforce I noticed there is an English-speaking bloc that winds up being technology early adopters," he says. "A lot of the technology comes out of Silicon Valley, where we speak English: the UK, Benelux, Australia are one bloc from an adoption standpoint. Whether you know it or not, you are in those countries.

"We were seeing Germany and France coming on quite strong. And we are as bullish on Europe as North America. We think the growth rate in Europe is huge, but we were really dragged into it. Our first big customer in Europe was [publisher] Reed. Touring Club Suisse is a customer, but we don't have anyone in Switzerland. They came directly to us and said they wanted to use our stuff."

Zuora's focus is on back-office software, an unglamorous but potentially enormous market, especially as businesses move towards online sales and selling their services by subscription. Tzuo calls this the "subscription economy", and suggests that the large business-software companies - SAP, Oracle and Microsoft - are struggling to adapt their products to suit it.

"My fundamental realisation for the idea for the company came when I was at Salesforce. At Salesforce we talked a lot about a technology shift to 'multi-tenant' systems which was really driving the whole software-as-a-service industry, but we also talked about a shift to a different business model. A pay-as-you-go business model where people would not want to buy software as CDs but instead would subscribe to services over the internet.

"You see this in the media industry, with paywalls and the desire to monetise online content, and with internet services from companies like Zipcar or Netflix. This broader trend was really a big, big transformation away from product-centric models - selling widgets, if you will - to a customer-centric business model."

Salesforce.com is about the front office, suggests Tzuo; Zuora is about the back office, about "pricing and packaging" services and managing the relationships with customers.

Firms report that using Zuora has not just saved direct costs when set against conventional finance, billing or enterprise resource planning (ERP) software. It also saves money by reducing the number of invoice queries and, in turn, the number of disputed or unpaid bills. This is at least in part because Zuora is more automated, and easier to use, than older systems.

"Existing ERP systems are designed for that product-centric universe, that manufacturing mindset. But companies are shifting to these new business models because things are moving to the cloud.

"In this environment, ERP systems don't work any more. They don't help you manage your customer relationships, they don't tell you how many active customers you have or your customer-retention rates. They don't help you design the pay-as-you-go pricing models that customers are demanding."

Operating in such an environment poses challenges. "When we started four years ago, we said let's embrace an all-cloud model. No servers, no IT department," says Tzuo.

But as Zuora outgrew its own financial-management software, it was unable to install a more powerful system.

"There wasn't anyone I could tell to install it. We had to go cloud - we'd bet on an all-cloud infrastructure... The more you embrace cloud, the more you are almost forced to embrace cloud going forward."

And this is the challenge for Zuora. Cloud computing is a powerful tool for businesses that understand its limitations. But it will not suit every business. Rival software companies are unlikely to ignore the challenge from Zuora. And they will no doubt counterattack using Tzuo's very own arguments. Not everyone wants to do everything in the cloud. At least, not yet.