HI. I'm a noob too. The word "Fiat" as it is used around here refers to your traditional government-backed currencies (US Dollar, Yen, etc.).
From what I can tell, the difficulty required to solve a hash is becoming overwhelmingly difficult due to significant advancements in technology used for mining over the past year as compared to previous years. The protocol is set up (paraphrasing) so that a block is solved, and thus bitcoins rewarded to the winning miner, once every 10 minutes. With so many people joining the network due to bitcoins increased popularity, and so many people mining with "mega machines", the hash has to get extremely difficult to solve in order to maintain a constant drip of bitcoins into the population. Therefore, it is hard to calculate the probability of you getting any exact number of bitcoins unless the service you sign up for upgrades their hardware to keep their hashing rate proportional to the growth rate of technology AND the population. This seems highly unlikely to me...but, again, i'm a noob.
If you have a few extra computers laying around with some solid GPUs, maybe try mining for other cryptocurrencies?