These marketing funds are typically not big (certain in AMD's case they can't afford it) but if you remember Dell/Intel fiasco where Dell would not use AMD chips during the Athlon dominance era even when Dell's customers (mostly server side) were clamoring for AMD solutions - well, Dell was caught trying to explain additional billion or so in profits that seemed to have no valid source. Yep - that's Intel throwing their marketing money around - so much so that Dell couldn't find legit ways to "spend" it to make it look good (this is my opinion btw).
I think you are missing a point here. Marketing funds will only work if your product is good enough to have a very lean cost structure and good enough to fetch a good price structure, enough to cover all the costs and still make a reasonable profit.
The primary indicator of this is the gross margins, and this is the reason Intel seems to be really focused on it. If Intel has a good gross margin they might even have an inferior product, but they will have a lot of maneuvering room with OEMs and in the channel.
AMD does not need high revenues to get into these same sort of schemes, they needed high margins and lean cost structure, something they did achieve some times in the past. They were really obsessed in making the K8 and K10 die size small, and the main reason to die salvaging X3 and X2 chips were to improve the cost structure of the business, and give the OEM all the money they need. That's why they were able to offer OEMs, for example, 1 million of chips for free (but still were turned down in the specific case). In the end, AMD market share grew even with Intel marketing practices.
Today AMD is taking a battering in the OEM market because they threw every cost consideration aside with Bulldozer. You simply cannot compete selling chips twice the size of your competitor, and this is why the thing has been losing share all the way in every market segment it is in. Even if the chips were to provide good performance, AMD would still have a bad cost structure and business would suffer, albeit less because the better price structure would soften the effects. With such a cost structure, you lost one of the pillars of your business, you can't really blame your competitor when you paint yourself into a corner like that. Bulldozer poor performance is just the icing in this poison cake AMD baked for itself.