(Updated in 2018)
We will get free shipping when we buy items on Amazon for a certain amount. For example: When we buy more than $25 ($35) on Amazon Canada, or buy more than $49 ($25) on Amazon US, we will get the benefits of free shipping. (Note: If you are an Amazon Prime member, you can get unlimited FREE Two-Day Shipping on eligible items with Amazon Prime. No minimum spend is required to qualify. Check US Amazon Prime or Canada Amazon Prime)
You receive free shipping if your order includes $35 of eligible items. Any item with “FREE Shipping” messaging on the product detail page, that is fulfilled and shipped by Amazon, is eligible and contributes to your free shipping order minimum excluding taxes, gift-wrap, Gift Cards, oversize, and heavy items.(From Amazon)
But when you buy something on Amazon, the unit price of the item is often lower than the free shipping price threshold (ie: $35 CAD or $25 USD). We need some other low-priced items as fillers so that the total amount we buy can reach the free shipping price. For example, on the USA Amazon, if the free shipping threshold is $25, and the item that we want to buy is asking $20, then we also need to buy at least 5 dollars of other items to meet the free shipping requirements.
We can either choose a free Amazon Filler Items Finding services such as SFiller.com:
OR, we can directly use the following amazon filler lists which include useful but cheap items: