> And how do you decide which of all the thousands of blockchains to store your bits on? Bitcoin's one, because Bitcoin is a flagman of all cryptocurrency move

> And how do you decide which of all the thousands of blockchains to store your bits on? Bitcoin's one, because Bitcoin is a flagman of all cryptocurrency movement. If somebody invents better blockchain than current Bitcoin's blockchain, that improvement will be implemented to Bitcoin for the sake of trust to the cryptocurrency with the longest history. > So to preserve your data "forever", you'll need to constantly monitor the blockchain ecosystem, and make sure you copy your data to another blockchain if the one you picked first shows signs of decline. I disagree with you. All you need is make sure your tx is not orphan. Abandoning Bitcoin for the sake of new Bitcoin-like cryptocurrency is against the promice of Bitcoin. > Or just use a few copies of normal storage media, copying them to fresh media at intervals. This is a solved problem. Blockchain offers nothing here. You miss the point of storing some bits forever. Forever is 100% uptime, period.