So after non-combat pets Blizzard started selling mounts for $25, and immediately finds a hundred thousand buyers on the first day, or more, because those 90,000 people queue observed was only for the US version of World of Warcraft. Note that unlike mounts sold by several Free2Play games, the Celestial Steed of World of Warcraft is pure fluff. It is just a sparkly pony, looking cool, but it moves in exactly the same way and same speed as your existing mounts. That is if you already have the epic flying riding skill, your sparkly pony will move at epic flyer speed. But if you are at an earlier stage and due to level or lack of gold have less riding skill, the sparkly pony will be slower. In other words, you are paying $25 for something that has no real game advantage at all.
And in my eyes that makes this "good RMT". The sparkly pony does not make any game content obsolete, nor does pretend that the buyer reached some epic achievement. If you see somebody on a sparkly pony, you know he spent $25 on it (or €20). Is that an excessive amount of money for something nobody really needs? Most certainly! But does that make selling it, or buying it for that matter, wrong? I don't think so. Buying something excessively expensive that doesn't do anything more than a much cheaper regular version is called luxury, and most people like luxury if they can afford it. Actually people like luxury so much that they are even willing to fake it, thus fake Rolex watches and fake Louis Vuitton handbags.
Does wanting a luxury item which isn't even real, but just virtual, make any sense? Well, I'd say it doesn't make less sense than grinding something in game for many hours to get a similar item. Some of my characters do have "special" epic flying mounts like the Nether Drake mount. I wouldn't call a reputation grind an "achievement", so whether I spend X hours on getting a special mount or I spend X dollars is pretty much the same to me. Some people would do neither, some value their time more than their money, and for some it's vice versa.
Blizzard is going to make millions of dollars with this. Which will prompt them to offer more and similar items in the future. And as long as these items remain fluff, like mounts and combat pets, that is fine by me. I believe Blizzard is clever enough to know that lets say selling epic gear would be a huge mistake, so I don't see this as a slippery slope. I don't think lots of people will cancel their WoW accounts just because they are jealous of somebody else flying around on a sparkly pony. I just hope that Blizzard is using some of that extra money to speed up their expansion development cycle, because *that* is where they are losing customers from right now. The sparkly pony is not a big deal.