This was my original question - How could you use existing blockchains to provide a decentralized version of twitter? The
https://memo.cash/ mentioned above does this but poorly. I will look more into this option as I agree, this is probably the best option. If I found a blockchain that is secure and cheap to send transactions, maybe I could build a website that reads all transactions in said blockchain and replicates a twitter feed using the messages in each transaction. Could even require the beginning of the message to have a specific key to remove transactions not intended to send message.
You don't need to and you shouldn't use the blockchain of a crypto
currency to post messages. As I said it should be built on top of that blockchain for example a bitcoin
side-chain.
https://en.bitcoin.it/wiki/SidechainIt could also solve the issue with price to some extent as the tokens on that side-chain will be pegged to bitcoin and mining of the coin could be performed by the same bitcoin miners (
merge mined). In that separate chain the protocol can be anything you like because it is a semi-stand-alone blockchain so the transactions in that chain can cost whatever you want while it still needs bitcoin's security to operate.