* Identify all decision makers who have veto power on the work.
I have personally and have known others who have gone through the whole process, getting signoff all along the way, only to suddenly have a new decision maker introduced who doesn't want a new site at all (in some cases because he/his son/his college buddy built the original site and he's emotionally attached).
In one case this was a large, well-known retailer that I've purchased from many times. Met the developer at Pubcon. He said that a week before launch, after putting thousands into the new site, all of the sudden, the CEO walked into the room and said he'd thought about it and kind of liked the old site better.