I don't really shop online except making payments for services every now and then. However, on the buyer's part, one major benefit is the fact that you don't need to leave your house or bother about carrying money about. All you have to do is shop probably sitting down sipping moet(or coffee), lol, and pay using a card and the goods would be brought right to your house. Stress free, isn't it?
On the sellers part, especially those that only sell online. They don't need to worry about theft from customers, money to pay on running a normal store. They don't need so many workers like they would if they run a normal store which will cost them more money.
You see, it's a win-win situation for both parties.