SimilarWeb, a London-based provider of digital intelligence with offices in Israel and the US, just secured a $25 million-growth equity round, bringing the company's total financing to $65 million. It is a nice sum and for international investors that follow such things, the companies leading the round — Naspers and Lord David Alliance — are pedigree sources to be noted.

But SimilarWeb is the rare start-up that can already count such heavyweight companies as Google among its customers. So perhaps we should start its story there.

What's Up With the Web

The company's mission has been to, as Ari Rosenstein, senior director of Corporate Marketing at SimilarWeb explained to CMSWire, reveal what is going on with the web.

It provides many of these digital insights for free, numbering the users of these freebies in the millions. The more strategic of its offerings, however, are provided only to its paid customers, a group that counts in the thousands and includes large companies such as Google and Nike as well as many small businesses.

Google, obviously, is hardly its only paying client but it is the most interesting given that the search engine has its own very rich source of digital data on Web trends.

"We are helping them understand the markets in which they operate in," Rosenstein said of its client base.

How? SimilarWeb, Rosenstein explained, measures the digital world, admittedly a very big statement.

"We know what is going on with and inside every website and app," he said.

"Google knows the world of Google but cannot see everything else. It can't see, for example, what is trending on Facebook or within third-party apps."

And SimilarWeb can. Here's how.

3 Sources

SimilarWeb taps three sources of data.

The first source is the Internet's general infrastructure. "We work with many ISPs buying data from them," Rosenstein said.

The second source comes via the company online marketing research platform, in which hundreds of millions of people around the world participate. The company has gotten participants, whose data remains anonymous, by offering SimilarWeb's software for free in exchange.

The third source some from the internal analytics programs of the apps that are being measured. A surprising number -- about 100,000 Websites and apps -- are willing to share this data for various reasons, Rosenstein said.

The end result is that a user can see, for example, what happens on a particular app after it is downloaded in terms of retention and engagement. It also can show which app or Website might be performing better in certain metrics, compared to a competing app.

The platform is very easy to use as well despite the mammoth dataset, Rosenstein said.

"I have had several Google managers tell me they bring their laptops to meeting so they can pull up data from us and show colleagues or a client specific trends," he said.

The New Funding Round

With this as background, the new funding round can be put in proper context.

SimilarWeb plans on using some of the proceeds for product improvement. "We want to go deeper to serve everyone in marketing," Rosenstein said.

Those Google managers who use the platform in meetings? SimilarWeb wants to see everyone in the marketing ecosystem carting laptops to meeting with SimilarWeb at the ready.

"We want to build the perfect tool for them all. So the person who handles mobile media buy can pull up the differences between mobile and desktop traffic on dashboards created for that role, and so on."

The company also plans to continue to grow its global base, both in terms of customers and employees. Besides London, it has offices in New York, Tel Aviv and other cities in Europe. The company recently launched a presence in the Ukraine for developers and hopes to use some of the proceeds to further its acquisition strategy.