select a winner for sentegy

winner.sql

SELECT * FROM 
(
	SELECT DISTINCT comfortfeedback.PersonID, 
			COUNT(comfortfeedback.PersonID) as c,
			people.name,
			people.email
	FROM comfortfeedback, people 
	WHERE comfortfeedback.TimeStamp >= DATE('2012-3-26')  
		   AND people.PersonID = comfortfeedback.PersonID GROUP BY PersonID
) as t1

WHERE c >= 4 
ORDER BY rand() 
LIMIT 1;