.BTC domains are registered through a smart contract on Stacks, secured by Bitcoin. This smart contract implements a decentralized name registry written in Clarity lang. Ownership of every .BTC name is represented in a hash of the Bitcoin blockchain. Instead of spamming the bitcoin blockchain with name registrations, thousands of Stacks transactions settle in a single transaction on the bitcoin blockchain.
Make the same offer on every item in a collection. A person can accept your offer by accepting the bid on their item in their gallery.