Yep. Most of the time for smaller items the seller doesn't even want me to send the item back. It's _almost_ no risk.

Not all third-party merchants have the same return policy.

At least in the UK, if you contact them and they don't resolve it, contact Amazon and you'll get a refund (and presumably they charge it back to the seller) under its 'A-Z Guarantee'.

That said, I've never bought higher value items from third parties via Amazon, so that may be a different experience. But I basically treat non-fulfilled by Amazon as eBay in terms of trust/expectations.

What reason do you put for the return? Because usually they end up charging a return shipping fee unless I drive to their hub.

Caveat emptor: if you process too many returns, Amazon will outright ban you from shopping there ever again. I know this might be anecdote, but it is true.

I'll hope and assume it's as a percentage of sales.

To be clear, I'm not 'taking advantage' like buying something I need to use once and then returning it out whatever - I just appreciate that if the item arrives broken, or not as described/fit for purpose that I can return it with minimal hassle.