Let's say that you are the leader of software engineers which will work on a big project this coming Monday and you just posted this valuable information in your professional online group as a group status but because of an unforseen reason, you had to cancel this for Tuesday since the management deemed that the project was prematurely thought off. Just imagine the inconvenience of having to notify everyone in the team that it will be cancelled when you can just revise the post and leave a "last editted on" phrase just below the message.
Also, what if you ordered something online and just a few moments later you found out the descriiption of the item unfortunately doesn't match the criteria of what you truly want to purchase? Just imagine the inconvenience of waiting for the shipment to arrive before you can cancel the transaction and return it to the company.
