This is a quote from the book "On Zero Confirmation Transactions" by Chris Pacia
...ersome, but it doesn’t mean that it wont work as a risk mitigation strategy. If you miss some change in miner policy, you will surely find out about it when someone exploits it, but at least t
hat’s only a one-time score. This is mostly what happened to Voorhees’ ShapeShift earlier this year. Miners changed their policy in regards to transaction fees, deleting transactions with fe
es below a certain value, while ShapeShift continued to accept them.
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The fact that ShapeShift failed to stay up-to-date with changes in miner policy, and paid a small price for doin...