If you wonder how you can earn alot of cash, its simple
if you don't know it yet, here is the biggest forum for digital currencys: https://bitcointalk.org/index.php?board=159.0
and every day are new coins coming out!
If you start mining on a fresh released coin you get a huge amount of blocks because the dificult is at early stage and very low
And after one day or more you can start selling your coins in the forum, or you wait until it hits a exchange site ( then it reaches real value ).
I already made 16 Bitcoins with this strategy, and i only have 500 kh/s mining speed, thats pretty low ( nividia cards sucks )
Good coins to stick right now are -> KlondikeCoin, DigiByte, USD-E
In one or two hour starts a new coin - Championcoin, get in before it gets released and prepare for it!
hope it helps you, enjoy the world of digital currencys :)