A friend of mine once ordered some items on an internet shop and when he reveived the package and opened it, he started jumping up and down while screaming like a young teenage girl at a Justin Bieber concert - We are talking about a grown man.
The reason why he was going crazy was because the shop owner had placed a free gift in the package.
It was not a expensive gift, but it was a positive surprise for my friend, who didn't expect to get something for free.
It can be a bag of wine gums with a sticky note saying, "Thanks for buying :-)"
It will be a positive experience for your buyer and it could lead to more a returning customer :)
So do yourself a favour and some bags of wine gums :)
Thanks for reading! <3