This hasn't really been Red Hat's only form of revenue, generally it's been subscriptions + qualified builds, etc, they've had proprietary software from time to time too. Red Hat Network and "getting the bits quickly", also.

Though it always seemed to me a large chunk of business revolves around banks, with major needs in areas like realtime, needing access and changes from some of the very strong kernel developers Red Hat typically employs. Smaller companies won't need support, banks are mandated to require it, and have very technical needs. This isn't "how do I chown", it's often very specific performance/timing/hardware related things.

While things may have changed, I remember Oralce making some noise, but not really getting any traction, and I don't really think IBM was a big predator in any case. Customers would know they didn't have the specialization.

Anyway, if I had to use a broad brush, Red Hat support is more key to Red Hat than consultancy - but yes, though they produce lots of products, they aren't a product company.

I think Red Hat is somewhat unique in this regard, as they are one of the few that HAVE scaled that way. Nebula seemed to be a product company, but it may have been true that their products required too much hand-holding to scale.