IBM also makes a large amount of money servicing and implementing other company's technology products, specifically SAP and Oracle (and probably a lot of Microsoft too). To me, they are a technology services company providing consulting, implementation, and outsourcing services, and they also happen to develop some of the technology products that they sometimes implement.
That assessment of IBM is way off. They service other company's products insofar as is necessary to develop complete integrated systems for their customers, systems they build mostly with their own technology elements. In some cases, they build systems entirely with their own elements (a Power7 machine running a DB2 server in AIX, for example). Their relatively recent acquisitions of companies like Rational and Telelogic were moves to own more of what they service. Owning and developing the hardware and software they sell and service is core to IBM's business.
