Won with free points on a gacha app

There's this gacha app with a green icon and a Japanese name. I saw it in an FB ad and downloaded it on a whim. I didn't spend any money. I used the free points they gave me to draw a card pack. At first, I thought it was just a card pack and wouldn't be deliverable, but then there was a delivery button. I pressed it and they didn't charge any shipping fees. It arrived in about 2 weeks~ When I opened the pack, it was all common cards, no shiny ones at all. It was pretty fun, but I don't think I'll spend money to keep playing.