Been using ING for over 8 years now. Logged into my ING app and saw a little alert (easy to miss) to say that I got a bonus $100 in my Savings Maximiser account.
No idea how I qualified or if this is part of a deal. I use my Orange Everyday regularly but for the past 3-4 years, I haven't used the Savings Maximiser account at all. Just thought it might be worth checking your ING account to see a little bonus!
Gee, ING is feeling generous recently!

I'd say you received a referral bonus from someone.