More uses of Wayback Machine?

The Wayback machine, we all know can be used for checking the age of a domain. Is it not?
And we use it before buying websites, or just checking the authority etc. But what can be done beyond that?

Gabriel Goldenberg has found that the wayback machine can be used for three more uses other than the age thing.

1 – For Checking Change of Ownership
2 – For checking the old URL and
3 – To check what was already done before you signed in

Here are the details and the original post. A good read. Thanks Gabriel.