I also give them a book along with the treats!
A side note--towards the end of my time sitting in front of my school 4 middle school aged boys were coming down the street and as they huddled together about a block away I thought "oh great--what are they planning?" and to be honest, I was a little nervous. I was sitting in my lawn chair huddled in blankets since it was a bit cold and here they came. I chatted with them and gave them some candy and as they walked away two of them held up some money and said, "We saw you from across the park and thought you were homeless....we were coming to give you some money." Aww....made my night and really touched my heart.