Do you collect stuff? Have you ever noticed that in the process of collecting one type of item, you end up with a bunch of related stuff? I find that this happens often when I purchase lots off of eBay. I don't have any use for this extra stuff, and yet I cannot bring myself to throw it away.
Then I started thinking that this must happen to other collectors as well, so what if I could find people that are looking for things I've accidentally collection that may have stuff I want. When I was a kid I used to trade my duplicate baseball cards with my friends, why not trade some of these items! We've become so accustomed to buying the things we want that the practice of trading has all but faded away.
Now as I'm buying things, I will often ask the seller, "what do you collect?" and then check my inventory to see if I have any matching items. Then (since the stuff has no value to me) I just mail them the items and suggest a trade. That's right, I send them the stuff without striking a deal in advance. Before you dismiss me as crazy, ask yourself how much effort does it take to get the items you collect and then read on.
Here's an example. I collect funeral cards for Genealogy Today. In the process, I get a bunch of holy cards, some blank, some with prayers. Sometimes I'll buy a mixed lot of say 100 cards, of which 20 are funeral cards. Repeat this several times, and you get a large pile of non-funeral cards sitting in a pile.
Now, I can (and have tried to) sell these on eBay and get a few bucks back. Instead, in the process of asking sellers what they collect, I made a friend who collects holy cards and doesn't know what to do with the funeral cards he gets. Viola! An open-ended mutually beneficial relationship. I mail him any holy cards, he mails me funeral cards.
I do the same with unwanted military items to get WW2 war ration books. And am currently looking for someone who collects railroad items so that I can get more conductor business cards and seniority lists.
This has opened up a whole new acquisition channel which is yielding some fantastic results. So much so, that I'm even bidding on lots at the live auctions that I attend just for the purpose of sending to my trading partners.