Are they actually making money for you, or is this just for fun?

I ask because I have 2 and have been less than impressed with their stability and function. While I can mine for days at about 2.6 MH/s on each, that's not earning me more than a few pennies worth of coins a month.

I picked up a couple of Antminer L3+ for $99 each and since I'm running an oversized solar panel system I don't have to worry to much about electric costs. At an average of 570 MH/s they're on track to make between $60-90 a month each.

I'm just curious why you want to invest more in them if they aren't really making anything.