I like it, this make us away from online upload services...
instead of paying money or crypto for encrypting your files and making it secure you can learn the basic programming and make your own free software to encrypt and secure your file if they are getting money from you this is useless there are free and open source software to deal with
You will pay nothing, they just take small fees for transaction.
the question is WHY would anyone in his right mind do that? it is literary "masochistware" as stompix said!
if you like the idea of it then do it on your own. how? just use two keys, encrypt whatever you want with them and then hold one yourself and hand another one to another person you trust or simply store it elsewhere. you don't have to use a third party to encrypt-decrypt your data. it is not some secret technology that they are using, it is open source and for everyone to use.
it can simply be a long password (60 char long) and you store 30 character of it and the other person the other 30 and encrypt your data using one of those password managers (trucrypt,...)
Why need this if you can use winrar? Winrar encrypts and secure files greatly and the fun fact is you hold the password. No need to pay even a cent.
Your idea is good for one or two persons you already know, but what about sharing it over the internet ? How will you manage to get your payment ? Here come sych innovative service ... if someone pay to decrypt your archive, you will receive instantly your payment.
To be honest, it is something similar to e-commerce website selling digital goods like software or ebook. However, it can protect the files only up to level 1 and after decrypting, there is absolutely no way to restrict further sharing of such files. It's not the legal ransom but kind of utility to accept one-time licensing fee against the sold digital goods.
Yes i see it like that ... but you can't prevent someone who decrypted the file to share it ... it's like an online ecommerce service or any other selling platform ...
Some guys here didn't got the concept ...