Marketing MMORPGs is hard. That's because what is actually interesting about them is not the minute-to-minute gameplay. Even WoW's very well done minute-to-minute gameplay is not good for marketing at all.
Imagine you could make your dream MMORPG. You have a team of 100 skilled people and $500 million to spend. Now, 8 years later, you are almost finished and about to go to E3 to present it. What do you show the public?
There's little you can show! The fun about the MMORPG is just not presentable within a few minutes - or even hours! Players play MMORPGs completely differently when they are just a demo; or a beta. Remember when Warhammer online beta players said that during beta there was so much more PvP everywhere? That was because people don't focus on leveling or equipment during betas!
What is especially bad is presenting the single-player experience 1:1. It has to fail! In fact, if you make the single-player experience bombastic enough to have an effect on E3, your eyes will bleed once you do any group content !!
So what do you do? Well, one thing are trailers. While Adam is right that these movie clips don't tell us much about the game, they are still a smart thing to do for Bioware. Firstly, because they tell the potential customers about the setting and gain some desperately needed attention. Secondly, because they work like a $1000 ring for your new girlfriend. She’ll claim that it is the best thing ever. What she really thinks is that you wouldn’t do this, if you weren’t serious about the relationship.
What these clips tell us is that Bioware is serious about our future relationship. They think that these clips are worth it. It is the one reason why waste is useful. Only by wasting resources (like buying expensive rings) can you credibly convince somebody that you are serious. That it is expensive and wasteful is exactly the point of this part of game theory.
The actually gameplay of a MMORPG, on the other hand, is rather useless. If somebody had shown me a farmville gameplay video pre-release, I hadn't been impressed. And considering WoW's graphics, I probably hadn't even been impressed by WoW. However, WoW is a bit special, because at this time the single fact that you could run around in 3D was the main information carried.
So, my advise for you wanna-be MMORPG marketing guys: Trailers work, but they are expensive and wasteful (that's exactly their point!). Also, people will blog about the fact that these movies just aren't the game. If you don't want or can't do trailers, don't show the single-player gameplay. It's impossible to make it appear sexy within 30 minutes, or even a day!
Instead, show everything that carries an instant feeling. Raid encounters were a good idea, if the community weren't so fed-up with big, stupid, scripted bosses.
If your game offers massive elements (like massive open-world combat) show it. But careful with doing it from a single player point-of-view. These things often look bad this way. Show it from a above. The real information here is not how it looks, but the 'massiveness' of it. This 'massiveness' is what you will feel later when you do it in-game. You need to adress the people's feelings. People don't play MMORPGs for the instant-action engaging gameplay; and thank god, they don't !!
If you have wonderful castles and large labyrinths, show them. But not by running through: without actually being immersed this is boring. Show them the map, or a fast-forward run-through. Or employ a narrator who describes the atmosphere well.
You may think that your task is to inform players about the actual in-game experience. But even if that were right, there's no way to do it! Playing four LFD dungeons in a row for that new sword can be great fun. But it is entirely unsuitable for marketing!
Imagine someone showing how achievements pop up in the game. Ridiculous, right? The emotional connection is what gives these things meaning. They are not meaningful in themselves; most things in life aren't.
Oh, here's a perfectly boring SW:TOR gameplay preview. Have mercy.
And now have a look at the CCP marketing! Perfect mix of in-game and out-of-game material to sell a feeling that feels authentic (that's why in-game footage is important!).
The point is that CCP's marketing is not only more effective. Of course, it is. But it is also more .. informative (aussagekräftig)! The reasons you are going to play DUST 514 are not possible to be presented by showing 12 minute gameplay examples.
When you play a MMORPG you are emotionally invested. This emotional investment has to be artificially created by the marketing department.