Both, but I think the ability to spend it make me feel that bitcoin is a real money!
BTW, where did you get your tips from? Are these tips in bitcoin or fiat?
Oh I'm a waiter XD
So you convert them to BTC every night? How? But however you do it, this is a good way of accumulating bitcoins, use the salary to make a living and save the tips for future. As for me, I like to hodl it as much as possible but I do spend it where I can.