Should be a given but also add, "On promised delivery date at time of order verification (eg. yer wallet says the Tx went through and has a couple verifications or check/other fiat xfr was approved) subject to strictly defined definition of "Late/delayed" and resolution process if late or delayed"
This comes to mind on both points:
http://web.archive.org/web/20131003021440/http://advancedminers.com/bitcoin-mining-hardware/520-ghs-bitcoin-miner from Oct. 3rd 2013. Ordered mine Feb 28th 2014 when it was not pre-order but instead "delivery in 4-wweks or less"... We all know how the AMT/Bitmine.ch A1 saga is progressing for most folks...