I find this way more interesting to be used for storing third party data that can later be verified.

What I still dont get from this post is if the data stored and timestamped can be "big".

For example, if I wanted to store 10000 sessions per second, would it even be possible via the blockchain hash? For the sake of the conversation, lets say these are orders on a very large web store, and I want to store the price + time of the order of an item.