Yesterday afternoon, I took my entire bitcoin holdings (0.1352 BC) and transferred it to my CEX.IO account. CEX.IO allows me to trade my BitCoins for units called GHS (Gigahertz/second). This payment is used to buy time on a system that is mining new BitCoins. Every quarter of an hour, it returns a portion of a new bitcoin to me in “rewards” (think of that as a stock dividend).
I used the 0.1352BC to buy 5.64GHS, and then started receiving those BC rewards. After about 12 hours, I gained 0.00046365BC in rewards. Converting that into US dollars, I gained $0.28 in half a day.