Better way to get credits.

Could there be a way of getting credits that isn't about spending money, waiting 24 hours or inviting friends I don't have? I spend most of my time telling the DM that I'm waiting because I can't do anything than I do actually playing any game. Why can't I come back every 5 hours to roll a die for credits? Even a smaller die roll than the d20 I'd take at this point.