Over the past few weeks in The Protocol, we’ve documented how Ordinals inscriptions, colloquially known as “NFTs on Bitcoin,” are adored by fans, appreciated by fee-hungry miners, and hated by some blockchain purists. A big hit earlier in the year, they’ve now fully caught a “second wind,” as Reflexivity Research put it, helping to drive up Bitcoin transaction fees to an all-time high. They’ve also gone mainstream: Last week, a trio of Ordinals inscriptions from the “BitcoinShrooms” collection – two Super-Mario-Style mushroom characters and a pixelated avocado – sold at the famed Sotheby’s auction house for about $450,000, or five times the highest estimates; needless to say, there are plans for more sales soon. The inscriptions fad has even spread to other blockchains, with similar technology clogging up networks including Arbitrum, Avalanche, Cronos, zkSync, The Open Network and Celestia, according to the analysis firm FundStrat. Greg Cipolaro, head of research at Nydig, noted in a report just how backed up Bitcoin’s “mempool” – the backlog of transactions waiting to get processed – has become. “The transaction queue stretches across an astonishing 372 blocks, equating to nearly 2.6 days based on an assumption of 144 blocks per day,” Cipolaro wrote. The takeaway? Users will have to pay up to get those transactions cleared faster. “Fees are now playing a much more substantial role in miner revenue,” according to Cipolaro. The extra revenue could help to offset the expected impact of next year’s “halving,” when block rewards are set to automatically adjust lower by 50%. But the scenario could also force a deep rethink (or revolt) on the part of users or businesses who may have predicated plans on the expectation of cheap transactions.