Can you sell a smell?
4 July 2014 Last updated at 16:47 BST
Of all the things to sell online, the last thing you might think would be successful would be a smell.
Selling visible items would seem like an easy pitch - after all, you can put the picture up on the website. But a smell?
Stephen Evans meets the German company that has gone from boom to bust and is now fighting back to deliver scents customised by customers.