Leave it to economists to point to the dead-weight losses associated with giving gifts. Here is the formal argument. "Scrooge" catcalls usually follow. Then again, markets do help with those unwanted gifts.
What about the joy of giving? But best of all, here is Joyce Carol Oates on the joy of getting (perhaps overlooked in most economic models). This is from her excellent The Lost Landscape (2015, p. 312):
"Look, Daddy! This is for you -- my brother and I would plead with our father, who might be reading a newspaper, or involved in one or another household chore, and would barely glance at us.
"We'd thought our father so strange, not to care -- not to care about a present.
"For children, even for teenagers, nothing seems quite so exciting as a wrapped present. For days beforehand my brother and I would speculate on the contents of packages beneath our Christmas tree, ..."
Note the importance of the wrapping. Torn open in seconds but nothing deadweight about it.
More stuff missing from the GDP tallies.