Marketo, Responsys and Silverpop declined to comment.
The large enterprise technology groups have varying needs.
IBM acquired Unica in 2010. Ovum's Brown notes that it has made tuck-in purchases such as
, and may not be looking for purchases in the marketing automation realm.
Oracle acquired Eloqua, which Brown said is "really a business-to-business proposition," and could have interest with a company like Responsys that has a strong position among retailers, airlines and financial services.
Teradata leans more heavily to business-to-consumer marketing, and could find an entity such as Marketo, with strength in business-to-business marketing, especially hightech.
Salesforce still lags behind companies such as IBM, Brown said, and could pick up more pieces.
Even with these vendors' vast offerings, there may be gaps to fill. Automating marketing e-mails and coordinating with social and mobile media can be a strategic entry point for a range of services.
"Once the large customers get a taste for it," Ovum's Brown said, "it can turn into a very lucrative cash flow stream."
Written by Chris Nolter