Premise:

A Tupperware party is a social occasion where a large group of friends meet in their homes with a Tupperware sales agent who then sells them stuff at discount prices and gives away free goodies on the notion that as a group of friends the participants will be more likely to purchase lots of merchandise and have a positive association with their brand name.

In essence, a personal expo w/ a company agent giving away free promos to a group.

My idea is to merge this notion with that of a LAN party, or a boardgame night. On a college campus, or in someone's home one would schedule a developer/publisher specific event each month where a representative would come demo their product to a large group of geeks, offering free incentives or discounts.

The principle is the same: when large groups of familiar people are together in a place with free stuff at a fun event (game expo) they are more likely to buy in-game bonuses, promos, expansions, and other catalogue items, and tell their friends.

Imagine Z-Man or Fantasy Flight setting up large game nights in the homes of fans, where a single agent comes with a small library of goodies and games, and comes prepared to teach/run a handful of games, and sell them.