No. Since each is a Gift and is less than $14,000 there are no taxes.
The average donation is $30
It's a gift to the person who opens the gofundmen site. In this case that isn't the people who run the pizza parlor. From a legal standpoint when the money is given to the pizza parlor then is it one single gift of hundreds of thousands of dollars, in which case gift taxes apply? Or is it still thousands of individuals, in which case they wouldn't?