I don't think you read my last post fully. This would not be just a time stamping service, it would be a service where you can store a whole file on the blockchain in plaintext such as a jpg or pdf or whatever, then the file is stored forever.
The file is not "stored forever". Only until the last "miner" on the blockchain.
The benefit of the blockchain is the file is stored in multiple places and cannot be taken down.
Do the same thing by saving a file on a cloud service. Much less bandwidth and you don't need to worry about it being taken down... unless it is illegal, which is all your service would be good for. :/
If I want to post my annual investor's share report, I don't need your system. If I want to post a naked picture of my ex, I do. How long do you think people will use their bandwidth to transfer garbage?