What is Brand? Big question really. CharlesRyan, Griffith Dragonlake and Delta have all touched upon it. I'd go with what they say.
And I do mean a big question: there's whole marketing degrees out there that try to answer this question. None of them have yet managed to get the essence of Brand quite worked out. Nor do I think they ever will. It's been a long time since I did any marketing (it was related to my TV studies and so I did a little back in the olden days) so please forgive the vagueness of the following.
It is most definitely a system of individuals identifying with a certain thing (idea, concept, collection of icons, shared experience and many more) in a way that gives fulfilment (again a nebulous concept that can vary greatly from person to person and situation to situation) to those individuals. Brand is a concept that exists in the minds of those who wish to partake in the Brand and is, I believe, unique to each individual. As an example, just look at the answers to the thread above. Brand exists in the interaction between the owners/sellers of the brand and the the buyers of the brand. ALthough perhaps better words would be Evangelists of a brand and Followers of a brand.
The real question marketers want answered is "In what way do people interact with Brand?" Because of course if they know "How" they can then manipulate the market. This will never happen, there is no magic bullet, no simple answer to the question.
One thing that makes Brand so hard to pin down is the fact that the system feeds back into itself in an intelligent way. It reacts to itself then reacts to those reactions. I'm no expert in Chaos theory (understatement) but isn't this going into that sort of area? And doesn't that make it kinda hard to predict? Oh, you can predict general trends. But it can be very hard to predict the results of a major change or even small changes over time.
Brand can take on a life of its own that goes well beyond the mere ownership of the logo/intellectual property et. al. Just look at the New Coke debacle of a few years ago. Sure Coca Cola Company own all the plants, the recipe, the logo, the trademarks and what-not. But they better not try to change the thing itself. (Well, not again.) Because an inescapable part of the coke brand is the taste of the thing. But people didn't just complain about the changing flavour. One heard things like: "It's what I grew up with." "How can they change something that so many people have loved for so long?" I paraphrase but that was the gist of many anti-New Coke activists. It was shared experience and the associations that came with it.
This is one of those object lessons that must be making the folks at WoTC nervous. Are they gonna get a New Coke? I'd say probably not. A major difference that I can see is that they are letting the market take part in the decision making. Or at least believe they are. They are using much more subtle forms of marketing: that whole "viral" thing that is very trendy in marketing circles. From memory Coke didn't do any of this (viral marketing was only in its infancy back then, relegated to bands, edge theatre, anything involving students,that sort of thing.) The Lords of Coke just handed down a Pronouncement and expected everyone to go along with it.
What is the DnD brand to me? (hey, I got around to it at last!) There's a generic component, not limited to those products that sport the DnD name/logos. Rolling dice, telling bad jokes and generally hanging out with my friends. It is also the memory of experiences shared with friends. Memories dating back to the early 80's for me. There are also specific tropes that I expect from a DnD game (as opposed to, f'rinstance, a Supers game.)
Tankschmdit listed many of them:
1. Strong archetypical characters working together: at minimum fighting man, magic user, and cleric are necessary.
2. Vancian magic and spell levels.
3. Armor reducing chance to be hit, as opposed to absorbing damage. Armor options must include at minimum: unarmored, leather, chain, plate, and shield with any of the above.
4. Divine magic separate from arcane magic.
5. Alignment, whether it be one axis or two.
6. Six ability scores, typically rolled on 3d6.
7. Silliness inherent in many monsters: owlbears, gelatinous cubes, the bullette, the rust monster.
8. Class based and level based.
9. Hit dice, which will cap at name level or the equivalent.
10. Races include at least human, dwarf, elf, and halfling. Races need not be separate from classes.
11. Flavor of the rules based heavily on early to middle 20th century sword and sorcery and high fantasy writing.
12. D&D is organic; if you leave out a couple of these, you can still argue you are playing D&D.
I'd say I could miss many of these and still feel I was in DnD. I could probably miss all of them and say I was still in DnD. Why? Not exactly sure but as each new edition has grown from a previous in a recognisable way. Just like I'm still me despite bearing little resemblance to the small squalling thing my mum brought home from the hospital all those years ago. Everything has changed but I'm still me.
So maybe continuity is the thing. Although this is isn't a necessary condition, otherwise there could be no new brands.
just some ideas.
cheers all.