We normally use an innovative way of selecting the winner through a unique random number generation method provided by www.random.org

The way the www.random.org random number generator works is quite simple :-) "A radio is tuned into a frequency where nobody is broadcasting. The atmospheric noise picked up by the receiver is fed into a Sun SPARC workstation through the microphone port to generate a sequence of random numbers. Note that, here each number is picked independently of the others (like dice rolls), and a sequence of numbers may therefore contain duplicates".

We typically generate a sequence of 10 random numbers using the unique respondent ids. and pick up first id as the winner's from the sequence. The idea is to have a list of 10 possible winners; in case we don't hear from a winner within a week of sending out an email we can extend the prize to the next person in the sequence and so on.