I have a small brand that creates a product in the health/wellness sphere. Every now and then (including recently), I'll get requests for people asking for free products. Usually, something about how they really think our product could help them, but they can't afford it right now. Just curiuos how anyone else handled this.
I would say this depends on the type of "customer".
We also regularly get asked for free products, but normally this is charity companies requiring items for auctions etc.
Usually we come to some arrangement where we supply a handful of products and in retrun get some backlinks and social media exposure.
So if these customers are businesses then try the backlink approach, but if they are normal everyday people then nudge them in the direction of creating some sort of social media post / review if you send them something.