Not much..certainly I'm not giving up the day job...yet!
i asked a similar question and had feedback about my hubs saying things like my hubs were personal opinion and I presume this meant they would not earn much but when I looked at high earning hubbers many of their hubs were opinions...so go figure.
I've tried backling, google word search, etc etc and have had a few flurries but nothing to write home about.
I'm still trying to work out what the tricks of the trade are.. a little confusing because when i read some hubs of people who I believe are earning well I just don't find their hubs very interesting on a personal level but obvioulsy they have a good deal of followers who do enjoy their work.
So I guess i can't really see what is setting them part from the slow earners because i think it's all happening behind the scenes eg backlinking, other websites and perhaps something I've not discovered yet!
I don't think your earnings are "pathetic" I prefer to call them "full of potential" "aspirational", "growing", "full of promise"..good luck!