People have things they want to sell, other people want to buy those things. Some of those people will be coming to UKAStock, hence the birth of the UKAStock bring and buy thread. It's pretty simple, UKAStock attendees list the things they want to sell and how much they want for them. Other UKAStock attendees peruse said lists and offer to buy/trade. You meet at UKAStock and seal the deal.