Half! Half of the 31 wedding invitation designs that I created during my 31 day challenge in March were total duds, lead balloons, DOA.
I admit, there are a few in here that I phoned in - you can't be on top of your game every day. But I some was genuniely surprised that a few of the designs didn't receive a better response than they did, and a few that I suspected wouldn't be well recieved by 'the market' but I wanted to put out there anyway.
All in all, a good reminder that productivity and prolificness is half the battle.