# Gavin Andresen
# 2011-02-15 21:56:17
# https://bitcointalk.org/index.php?topic=3441.msg49451#msg49451

One more thought:  the "finney attack" can only be profitable if the reward from cheating is greater than (reward of mining times the probability your block will be rejected because you delay announcing it while you "run down to the store"). @p{par}

Reward for block is currently $50, that will (hopefully!) continue to rise for the next decade or two. @p{par}

Say it takes you 5 minutes to complete a transaction at the corner store (half the average block gen time)... today you'd have to make a $25-or-greater purchase just to break even. @p{par}

Seems likely this attack will be completely impractical for transactions under $200 when the block reward is worth more than $400.  0-confirmations (just wait N seconds to look for a quick double-spend) for any transaction under $200 seems "good enough" to me. @p{brk}