When you pay a cheque from another bank into your bank, the bank will often hold that money for several days, because it can’t trust that the funds are really available. Similarly, international wire transfers can take a relatively long time. Bitcoin transactions, however, are generally far faster.
What’s that you say? Your credit card transactions are instantaneous too? Well, that’s true. But your merchant (and possibly you) pay for that privilege. Some merchants will charge a fee for debit card transactions too, as they have to pay a ‘swipe fee’ for fulfilling them. Bitcoin transaction fees are minimal, or in some cases free.
People can’t steal your payment information from merchants
Bitcoin transactions don’t require you to give up any secret information. Instead, they use two keys: a public key, and a private one. Anyone can see the public key (which is actually your bitcoin address), but your private key is secret. When you send a bitcoin, you ‘sign’ the transaction by combining your public and private keys together, and applying a mathematical function to them. This creates a certificate that proves the transaction came from you. As long as you don’t do anything silly like publishing your private key for everyone to see, you’re safe.
You own it
There is no other electronic cash system in which your account isn't owned by someone else. Take PayPal, for example: if the company decides for some reason that your account has been misused, it has the power to freeze all of the assets held in the account, without consulting you. It is then up to you to jump through whatever hoops are necessary to get it cleared, so that you can access your funds. With bitcoin, you own the private key and the corresponding public key that makes up a bitcoin address. No one can take that away from you (unless you lose it yourself, or host it with a web-based wallet service that loses it for you).
You can create your own money
In spite of the amazing advances in home office colour printing technology, most national governments take a fairly dim view of you producing your own money. With bitcoin, however, it is encouraged. You can certainly buy bitcoins on the open market, but you can also mine your own if you have enough computing power. After covering your initial investment in equipment and electricity, mining bitcoins is simply a case of leaving the machine switched on, and the software running. And who wouldn't like their computer to earn them money while they sleep?