In Finland consumers have the right to return the product for 7, 14 or 21 days (depending on product category and if online/offline store). The merchant has very little control over this with the main exceptions being stuff like underwear etc that can not be returned due to hygiene reasons.
The product when returned still has to be in a state that it can be sold.
This also means that lot of people pointing out Amazons very liberal return policy being a good reason to shop there makes no sense here. We got roughly the same return policy for all online shopping. And as others pointed out EU regulations give 14day return policy for all online shopping.