I don't really see why confusion between themes would be harmful to sales.
Completely agree.. If you're into knights, some of novelmore will be nice. If you're into fairies, fairies will do...
AH, but then... they'd sell the stuff!
Well, imagine if LEGO would have launched not only NINJAGO, but also a Ninja Themed FRIENDS line and ... DUPLO Ninjas at the exact same time, would that not have created some confusion, and perhaps some adverse effects for the start of NINJAGO?
I don't think so. It would lead to a lot of people being overrun by ninjas... but I am sure Lego (unlike playmobil) would think that a fine thing...
IMO, of course.. all of it. Obviously.
Ages ago here, a detergent brand like Tide (was it them?) launched a new one. Yes, they lost some people from the original to that one, but also got some from others. If in the end the money is in their pocket, does it matter if it was the 1st or the 2nd one? Nopes. Money is money is money.