Bitcoin 72 Hour Mempool Expiration Is A Myth

If you paid the miner fees too low like 10 satoshis per byte and below, it’s a guarantee that your transaction will get stuck in the mempool for a long time.

Don’t believe anyone (like Okcoin) that say your bitcoins will be returned to you after three days of no confirmation. Nodes or Bitcoin clients can re-broadcast the transaction thus keeping the transaction inside the mempool in perpetuity.

Example: https://www.blocktrail.com/BTC/tx/a91c883580d9c1c67f0b26d71ef12ee77fc204b05fbc03dfcaa4db2486790e33

The only way I know to get it unstuck is to double spend it or use GreenAddress’ replace-by-fee RBF feature.

Next time before you spend bitcoins, check for the best amount of fees to pay at https://bitcoinfees.21.co/ or http://www.bitcoinqueue.com/