Bitcoin is just a virtual currency, but it is used as real money to buy many things. There are many people who accept Bitcoin payments for items, including online stores and regular stores. Popular online stores accept Bitcoins including Newegg, Overstock, Microsoft, Dell and more.
In the United States, there are Reeds Jewelers, One Shot Hotels, Holiday Inn, and even pizza locations, restaurants and more. You can even use Bitcoin to buy addictive drugs, gambling, bullion, or even donate to charity. This is the reason why I like BTC.
In Japan many merchandiser accept bitcoin as a payment, and I agree with you that bitcoin can pay online transaction like purchasing online, but the only problem in bitcoin is the traffic of it so it is better to use any other coin that has a low traffic, I heard there is a coin that just a second you will receive it if I'm not mistaken it was bitwhite and they have merchandiser that accept their coin as a payment.