The best reasons are:
No physical currency involve!
There is no physical currency with fiat these days.
There are still tons of it to go around, and there will still be tons of it to go around for a while to come. The problem I have with it, is the health risks involved with the handling of physical cash. We are exposed
too a lot of germs and bacteria and even viruses, when we handle physical money. Test has shown traces of faeces and blood on most of the money we use, and even drugs like cocaine. Our cash is filthy and
there are some serious bugs going around, for us to keep on handling it physically. { Ebola / Flu etc...} See this article :
http://www.economist.com/node/21564529/Regarding bugs and germs, what do you think would happen when we all start tapping our phones en mass against NFC terminals? The same thing as with cash: Massive transfers of germs, bacteria and virusses.
The only way to avoid most of these (non airborne) is by making a truly wireless method that does not require any physical touch against a central terminal that touches more than one person.
Bitcoin is a paperless, bank-less, state-less currency that allows people to pay directly for goods and services. The coins themselves are made by computers solving a set of complex math problems, and people who use their computers to make coins and record transactions are called miners.
The value of a bitcoin has fluctuated wildly since 2009 but now hovers between $400 and $450. To spend it, users buy bitcoin and transact using a third-party app such as Coinbase. Rather than a central authority validating transactions, all transfers are recorded on a public ledger. It can be used to pay for coffee, dinner or software from online stores as well as some real-world shops.