Paypal *looks like* its free too as long as you are on the *sending* end.
It is instant, chargeback-able and easy-to-use.
Annoy them in any way however, and you are toast with no recourse.
Bitcoins fundamental advantage in my opinion is that there is no middlemen.
It is a *free* (in terms of control, not just cost) currency.
There are no fees for sending or receiving using alipay.
The transactions can be instantaneous (relatively ofc).
Bitcoins has a middleman (the transaction fee & an escrow like clearcoin is required due to the cashlike nature of it). It doesn't have to, but that would be like doing a bank transfer in most countries. (free, no chargebacks)
Local currencies are a lot more convenient compared to bitcoins as you don't need to pay some service to buy the currency(mtgox 0.65%? 1% LRUSD? 2% EUR?). Local currencies are almost always readily available and at no extra costs...
How popular is the need for an anonymous decentralised currency? How much more are you willing to pay for a product for this priviledge....?