A good barter site or a good barter opportunity is when you offer (-X-) and ask what can you offer me in exchange. The barter only works if the deal is acceptable to both parties.
On a sidebar story to bartering. An old guy that I knew years ago told me about this drinking establishment in Toronto during WWII. It was for officers in the military and members of other federal organizations were allowed to drink at the bar and buy cigarettes and booze to take away. All the purchases were tax free and there was no profit made of the sale of booze and tobacco products because it was for military personnel. Many of the people allowed entry into this place bought booze and ciggys to barter with working girls. These items were in great demand due to shortages during the war. If the girls did not consume the products themselves the items could be used to barter at the grocery store for other items in short supply like milk, eggs and veggies. I do not know if this drinking establishment for military people was there before the war, but it as there during WWII and it lasted up to the 80s when the old guy told me this story. It may still be there, offering duty and tax free booze and ciggys.
Perfect example of where barter works: Where an item one has is worth more on the street that they paid/have invested. If both parties have something of similar description the opportunities are endless.

