To this day every IBM customer I've ever contracted for has also been a Red Hat customer. That even applies for mainframe shops. Sales reps and support and account managers at IBM and Red Hat had eachother on speed dial a decade ago since it was so common to work a ticket that involved both companies products, or sell a bundle that would include both companies software and/or hardware, etc.

My only question is what the hell took IBM so long in making the decision to buy them out. I've never been less surprised by a big acquisition than I was with IBM and Red Hat. The only surprising thing was that nobody outside of that space saw it coming.