My vote for best schwag goes to Amazon for their Amazon logo emblazened decks of cards they were doling out. If you were a student coveting the deck of cards it seemed you had to answer the question of what a link list is. With this crowd it seemed akin to asking a gardener to describe a shovel, but maybe the point was to make people feel like they earned the schwag.
I think he’s onto something. Although you may not want to set the bar high, using a giveaway to engage someone is probably going to be a lot more effective than just leaving it out on the table to be taken. Even one simple interaction can be enough to jumpstart a connection.