Yes addiciton you could say but I think of it more as a fun hobby no different that collecting/admiring nice fountain pens (I used to be into the maki-e pens, the old Parkers, Conway Stewarts, etc), wine, etc.
If you care enough about fragrances, you want to keep sampling. if You like wine, for example, you wouldn't just drink the same one that you liked for the rest of your life would you? It's fun to try new stuff and experience new scents.
What I've learned though is to sample in stores and buy decants, so that this hobby is affordable and doesn't break the bank (going back to the wine analogy - you dont buy every bottle of wine you go to tastings and sample so you dont go bankrupt).