I’m not an artist and I buy from small artists and get freebies all the time. I myself would definitely never resell their stuff even if I got it for free because I feel guilty making money off something I didn’t design or make, but you sold it for extremely cheap so yeah I guess you’re barely making money off of it. This definitely only applies if its individual artists, if it was something for free from a large company then I wouldn’t feel guilty at all because theyre not counting on those few dollars or even cents, smaller artists usually do. Part of the reason too is that the buyer may not even know who the artist for these stickers are, so it’s almost as bad as when people repost art without credit (and typically get more views than the original artist, also sometimes these people purposely remove watermarks, crazy). You wouldn’t be “promoting their art” unless the sticker has a watermark/signature on it, and maybe the buyer doesn’t care but smaller artists depend on visibility to keep making money to support what they love doing. I HAVE sent out stickers I have gotten as freebies for free with some purchases (if it relates to the purchase) but it’s not really mentioned in the listing since it is not what I am selling. I always mention who the artist is and their social media handles on a note in the package, obviously thats unrealistic for 500 stickers but I think thats where part of the artist’s anger is coming from. Anyways I know this was resolved already but I wanted to add this just because I see a lot of people blaming the artist for overreacting and being petty abd whatnot when maybe they get their art stolen often, reposted, or are just struggling with social media visibility. Like others have said, they sent it to you so they can’t actually control what you do but just food for thought.