To put some perspective on this, Intel's Marketing, general and administrative costs in 2018 were 6.7 billion[0] whereas AMD's net revenue was 6.4 billion[1].
I'm reminded of that any time I see cheap products with slick marketing (mostly fast food) - you have to assume they're cutting corners in their actual product to pay for all that graphic design and video editing.
Or their revenue and income are so massive that taking a bit from it for advertising is a drop in the bucket. Intel has revenue of nearly 71 billion/year vs AMD at 6.5 billion.
That may be true, but despite that they still cut corners. See Spectre and Meltdown vulnerabilities and the impact to the performance of Intel CPUs once mitigated. In fact, Intel recommended disabling HyperThreading if you want to be completely protected from the vulnerabilities.
Sort of. Maybe. But as an moderately large Intel customer, I assure you they are very afraid of any accusations of unfair practices or anti-trust behavior, so they are somewhat crippled in their ability to fight with money.
Big discounts, kickbacks, "deals" and "programs" are being deployed and more on the way.