I think you're absolutely right about the signature scent being a marketing trick, but it also kind of appeals to my romantic side : That there could be one scent that totally embodies me etc. Not likely though, since I'm not sure who "me" is most of the time 
Today wearing about 6 different samples (far from ideal, I know, but got a bit carried away) that came in the post today from histoires de parfums. I like Ambre 114 most. Blanc Violette wasn't quite what I thought it would be, but ok. Moulin Rouge was nice until the drydown, which on me us quite bitter. Tubereuses 1and2 are ok, but I meant to get the animale one, which everyone us always on about. 1826 has disappeared from my arm already. Oh well.
Tomorrow will baste
myself in the oils that came in the post today already.