That TS3 trailer is what sold me on TS3 though I don't even like moodlet and buff systems, lol. I remember being so excited when I first saw it. That's some good marketing. I was exactly like some TS4 players are here, who may not be able to imagine newer, better, innovation of an engine. I was like no you will never take my TS2, lol, from my cold, dead hands. I loved it so much, but then they came out with the TS3 trailer and I was omg! I have to see that for myself! Ran out to Best Buy early the morning of release to buy TS3. I loved TS2 so much but I wasn't going to pass up seeing how open world worked and all because of a marketing trailer. That's the sort of innovation (just think how much it changed gaming for The Sims by looking at that one house on an empty street) I want to see, now. Huge leap in innovation. I digress.
ETA: but I also think this current marketing team hasn't figured out yet, the voice actor they hire for their trailers can sometimes cause some to not to buy a pack (seriously) and or to buy a pack. TS4's gameplay trailer was ok but the voice actress grated on my ears, compared to the male voice actor of TS3's trailer, and or TS2's trailer. I have wondered why that is, and I finally decided I was turned off by the valley girl sound of the voice, like they aren't breathing in deeply enough to say every thing they need to say, and some voices grate and consumer doesn't love the shown gameplay nor the concept sometimes, because of how it was marketed. Compare which packs did very well for TS4, such as Vampires and which voice actors are used, and though a pack or new game may not be any better than a previous, the voice actor is the one trying to get people excited enough to buy so the ones I dislike most seem to be ones that didn't make me like the trailer to start with, even if the gameplay looked ok.