Ann: Share Purchase Plan Offer Booklet, page-31

I am pretty sure Phil has already covered this.
https://www.itnews.com.au/news/aussie-broadband-says-some-customers-are-switching-providers-to-get-high-speed-nbn-discounts-563411

People are simply chasing discounts that cannot be offered to existing customers. ABB also offered these same discounts during the same period of time. I believe some RSPs have continued some of the discounts for a period of time but based on costs, they are likely losing money.

ABB has always had a referral program in place, this is not new. The amount suggests they might have signed up to a business plan unless there is a promotion or change to the $ value for residential services.