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. So the site would allow you to put files on the blockchain and view them.
In short it allows arbitrary data to be stored, in the most common type of "package" - a file.
The cost of someone doing that would be too much. Have you stopped to think why other services only store text? And why it costs so much to even store text on some blockchain? Imagine the price for storing the file, and its not at all useful in any way.