Salesforce.com announced on Monday that intends to offer $1 billion in long-term convertible debt with an option to raise an additional $150 million. It's clearly a war chest for acquisitions, but just what will Salesforce.com acquire?

CEO Mark Benioff has made no secret of Salesforce.com's acquisition plans. Why bother? Benioff's goal to build the company to $10 billion in revenue is well documented, and that's not going to happen through organic growth alone, no matter how hot its existing sales and service offerings may be.

Salesforce.com sailed into marketing by buying social media listening company Radian6 in 2011 and social campaign management firm Buddy Media in 2012, but in doing so it headed into deep waters. Digital marketing is turning into a vast ocean of a market, and competitors like IBM and Oracle aren't fooling around. Oracle's recent purchase of erstwhile Salesforce.com partner Eloqua was a high-caliber shot across Salesforce.com's bow. SAP and Microsoft show signs of waking up to this opportunity as well.

[ Want more on Benioff's marketing ambitions? Read Salesforce.com Caps Record Year, Eyes Acquisitions. ]

It was no surprise when Benioff confessed, during the company's most recent earnings conference call, that Salesforce.com "needs to buy more marketing companies, honestly, because there's more for us to do."

One obvious acquisition target would be Marketo. That Salesforce.com partner was often mentioned in the same breath with Eloqua in recent years, but Salesforce.com probably held back, not wanting to make an enemy of one or the other. Now that Eloqua is in Oracle's hands, it could be time to step up the rivalry on another front. But Marketo, which has an IPO in the works, won't come cheap.

Marketo's IPO "could be on the Workday level," analyst R. Ray Wang of Constellation Research recently told Silicon Beat. That means around $630 million. That's not quite as high as the $689 million Salesforce (over) paid for Buddy Media, but it would still blow a big hole in that $1 billion war chest. So maybe that ship has already sailed.

What might make more sense, given that Salesforce would want to subsume its acquisitions into its own brand anyway, would be smaller and more tactical deals will lesser-known companies. Causata, for example, is four-year-old startup that's playing at the intersection of big data, marketing and real-time analytics. The company bills itself as a customer experience management company (the same lingo recently embraced by Oracle).

Causata's VP of marketing, Siebel veteran Brian Stone, recently told InformationWeek that the company's edge is in making decisions within 50 milliseconds or less. It's about sending out marketing offers while customers are still in a Web session or on their mobile device, and the company knows very well that it's playing in the same waters as Adobe with its Marketing Suite, SAS with AssetLink, IBM with Coremetrics and Unica, Teradata with Aprimo and now Oracle, which could combine Eloqua with its Real Time Decisions technology.

Benioff could be playing up marketing while keeping big data ambitions closer to his vest. Salesforce recently announced its own SQL-analysis-on-Hadoop open-source project called Phoenix. The goal is to support SQL querying on HBase, the NoSQL database built on the Hadoop Distributed File System.

It surely bothers the hell out of Benioff that Salesforce.com has to spend big bucks to run on Oracle's database. Meanwhile, far larger cloud-based companies like Google, Facebook and Amazon are running on combinations of NoSQL databases and distributed processing environments like Hadoop (or the system that inspired Hadoop, in Google's case).

Salesforce has been offering hefty headhunting bonuses recently to hire every HBase expert it can find, according to one source in the Bay area. Could this be a nascent project to move the Force.com platform and Salesforce.com onto big data infrastructure?

A strategic acquisition or two in big data arena could certainly accelerate such a plan. And it could also add big-data revenue potential to the Force.com platform. Here, too, Causata makes sense as it runs on HBase, but other candidates might include Continuuity or NGData.

The big data angle might be something for next year, but it's fun to speculate. Given the sober, "we're the customer company," messaging Salesforce recently launched, any acquisition will likely scream "customer experience." These big data candidates clearly have marketing in their cross hairs, but Salesforce.com stockholders might revolt if they don't see deals that will drive immediate revenue.