Just received an email from Citi this could be targeted
Opt in for 5% cashback (up to $100) on eligible retail shopping when you spend $500 or more.*
Eligible retail shopping merchant categories(www1.citibank.com.au)
Available to the first 10,000 primary credit cardholders
Opt in below and spend $500 or more on eligible retail shopping online or instore with your Citi Credit Card to enjoy this cashback offer.
August promo page (for reference only)(www1.citibank.com.au)
Someone higher up said Bundll doesn't work. Zip apparently does