For me, during my life this far:
1) read manga / watch anime as you said
2) traveling in Japan (it's an awesome country for travel)
3) communicating with my Japanese friends
4) studying here
5) living and working here
The economical factors have never meant much for me, the emotional/attachment/interest factors are the possible the only ones that could have kept me motivated to learn a language to a high level.
The economical factors have never meant much for me, the emotional/attachment/interest factors are the possible the only ones that could have kept me motivated to learn a language to a high level.