SendSocial promises to send anything to anyone, without needing an address. They suggest that you could use it to send gifts to Internet friends of yours, when all you know is their Twitter address.
How does SendSocial do this? By asking said Twitter person for their address, and then sending you a label to stick on your package. A courier then picks up said parcel, and delivers it to the mysterious Twitter person. And they charge £4 for a parcel weighing less than 2kg (which, to be fair, is slightly cheaper than what the Royal Mail charges).
It’s lucky that you can set up websites and company ideas for not much upfront cost, since it’s doomed to failure for the simple fact that if a person on Twitter didn’t want to reveal their address to a Twitter follower, they’re hardly like to entrust said address details to an anonymous company instead.
But hey, don’t take my word for it. Try it out. Send a random Santa present to my Twitter address