I already posted about Bitcoin and blockchain in 2017, on my birthday. The post no longer exists, but I left my Bitcoin address at the end of the post and received a donation from one of the owners of the exchange (a symbolic amount), something like $5 at the time. I don't remember the amount anymore. But if I had held on to it today, it would have made a huge difference and today it would probably be worth hundreds of dollars.
I emphasized the importance of Bitcoin and its technologies and expressed all my gratitude and expectations. This was in a Facebook group where I was very active and one of the owners/partners of the exchange was in the group.
As far as I remember, I haven’t receive any other gifts from any exchange. So just to summarize, it was not a gift received through an official promotion by the exchange, but through an individual action by the exchange in giving me a gift.