They're not lost, they're still in my hand, which means, better prizes the next day.
Carlos you are giving me free money, so I am reluctant to be critical, in fact the most important thing to say is thank you, so thank you.
However, if the goal is to encourage people to visit then I would try and figure out some creative way to recycle the "unclaimed" prizes in a random way. If you don't then there isn't any reason for anyone to visit coinad except for the four to five minutes per hour when you are offering a bonus prize. Surely that is not optimal for you to make back your investment.
Regardless, thanks for trying to help people who are new to Bitcoin.
msweb, I bow to your fast fingers, you 2 (or 3?) SRG 0 on the .05 prizes! Nice going!