Bitcoin has a number of practical advantages for ordinary e-commerce
That may be true, but it also has disadvantages such as scalability. AFAICT, every Bitcoin node must maintain an up-to-date ledger containing all transactions made to date: obviously, this is unsustainable in the long run.
The "fixed number of bitcoins" policy is also an issue. According to Bitcoin developers, having more miners makes the network more resilient to attack, in addition to speeding up transactions. Eventually, the subsidy to mining activity will become too low and agents will need to partially replicate its effect with transaction fees. This is sobering enough for a network which touts free transactions! as a selling point; however, what's more worrying, resiliency will also drop dramatically as mining activity slows. Paying a mining bonus would be more fitting, since the benefits of increased mining are shared by all holders of bitcoin.
The code can easily be modified to use only a partial ledger if necessary. It's not yet enough of a problem that anyone has bothered to do so.
"Free transactions" is more of a common misconception than a selling point, as SilasBarta discusses in the sibling.
We've started a habit of creating periodic Bitcoin threads to confine discussion thereof to those threads and prevent excessive proliferation of Bitcoin topics in the discussion section. Here is a link to the last one, which links the other discussions. Lot's to talk about, and another bounce in Bitcoin's value (up to 33 then down to 24), so share your links and thoughts!