Why did Lego gave me this from my purchase?

Could I get some understanding why did my Lego store in Australia gave me this card thingy, I’ve recently bought myself the new Batman Gotham Arkham set was so unsure why this card was giving to me? I’ve try looking it up and I’m unsure if I missed something or still don’t understand it😆 submitted by /u/XxkillerpyroxX [link] [comments]