my thoughts about this is...
what i never use, hate, feel i wasted my money on the next person absolutely loves and can not live without. so i do not believe there is any such thing as a notion that is worthless...i agree on subscriptions...i dropped all of mine, but have friends who love theirs. i have a whole basket full of (tools) that i never ever use...most are from friends who can not live without them so figured i needed them too. a couple i would probably use if i had any idea how :)
so it's all relative; and i love my bobbin tower!