If you take paypal for example, it moved $180bn in 26 currencies in 2013. If bitcoin got 10% of that market, say $18bn, it could potentially value a bitcoin at up to $800.
...
Unless the stress is on "potentially," silly.
1. You buy a Bitcoin from me for $200, using PayPal.
2. I use that $200 to buy two bitcoins a month later, again using PayPal.
3. PayPal has handled $400 worth of transactions, with only $200.
4. $200 is worth $400, QED.
That's how fractional reserve banking works!
It's a great way to count the same money multiple times and make your economy look far bigger and stronger than it actually is!
Sooner or later bitcoin will "benefit" from this too.