LOTRO had quite a bit of hype behind it on launch, but never really took off (wasn't sufficiently different from WoW to make an impact
What makes you say LOTRO didn't really take off? Multiple expansions later, it's still a very cool game with tons of players (though Turbine doesn't release subscriber numbers). If you mean that it isn't as popular as WoW, I'm sure you're right. But with 11 active servers (including decent European presence) and a 4 year run so far, I'd argue that it definitely "took off".