I'd say they have been successful with a lot of their acquisitions: BEA, PeopleSoft, Seibel, and many more. Also, I think they have been a better steward of Java than Solaris had been since Java 6.
All our clients (some with massive deployments for the time) dropped Weblogic and other BEA products the moment of the acquisition. Where did they do well?
https://www.oracle.com/corporate/acquisitions/