Four year old incentives

So, first my daughter asks for milk and then asks for strawberries. To keep the whole thing fairly short she asked her mother for the milk and her dad for the strawberries. Both parents lovingly rose to complete the task. In the midst of a genius moment she says let's have a contest and see who can serve me the fastest. Whoever gets what they get for me the fastest wins. Four year olds are smart. Incentives like winning are the best, don't ya think?