QUOTE(Grand. @ Mar 10 2015, 01:44)

HV isn't good way for credit.
Most efficient way is uploading
Not necessarily. With a high enough level (300+), playing all but Schoolgirl arenas on PF can give 250k+, and playing Schoolgirl arenas on Normal for trophies can give 50k. Add in a daily FSM and that's 30k more. Then, occasionally you get lucky and find something that might be worth auctioning for 100k-300k. Monster lab can give you an average of 1k-3k per gift (not sure on exact numbers), more if monster is high PL and more frequently gives mid- and high-grade. Multiply that by many monsters, and that's a good deal of income. There's also Dawn bonus if you have stars.
Add all that up, and that's something like 300k/day, if you're willing to play that much. With mage, it's much faster (but requires more expensive equipment for high difficulties).
I'm pretty sure that's much more than uploading can give you.