The guys at Blippy should make a search engine for all the products bought by their users.
For example, a prospective buyer would go into the search engine and search for "Harry Potter". The results would show:
- "Harry Potter and the Half-Blood Prince" book
(56 people own this - make an offer)
- "Harry Potter and the Chamber of Secrets" DVD
(43 people own this - make an offer)
Once you click "make an offer" blippy will show you a text box to enter a price.
Then, an email will be sent to all users who have bought the book in the past:
John would like to buy your "Harry Potter" book for 5$.
Click here to sell it to him.
Algorithms can decide when is the owner of an object more likely to sell a product based on past sales. e.g. send the email only to people who own a book for more than 2 months.