Online trading networks like Ariba's "take the guesswork out of finding the best business partner" and make those interactions more efficient, SAP co-CEO Jim Hagemann Snabe said during the call.

In one respect, the deal is surprising, given SAP's , a company with some capabilities that overlap Ariba's. But SAP may have been motivated in part by the large number of influential B2B e-commerce customers it will gain. Ariba's network connects half of the Fortune 500, according to Calderoni.

SAP plans to utilize both the Crossgate and Ariba technology platforms, Snabe said, although he didn't provide specifics. It also plans to bring its HANA in-memory database into Ariba's technology stack, as well as analytics. The latter combination will help customers better understand their spending and supplier relations, according to Snabe.

The Ariba deal is one of the latest instances of consolidation in the e-commerce and procurement software market, coming after of Emptoris late last year.

Startup Coupa could also find itself with some suitors. The SAP-Ariba deal "shows that some of the larger incumbents like SAP are trying to understand the cloud," Coupa CEO Rob Bernshteyn said in an emailed statement. It also gives companies like Coupa the ability to position themselves as independent from any given ERP system, he added.