Hello Danijel Dimitrijevic,
As far as I know tripleClicks whatches closely the items that are bought and sent to your customers, and If not mistaken you will not get paid until the customer has received the item and is satisfied with it! That might be a good way to reassure your prospective customer to trust TripleClicks, also remember that you can tell him/her to check the reviews on each item.
Hope this helps
Best of luck.