In the promo details, this indicates it is targeted via email but I found it sitting in my Seller Centre at https://www.ebay.com.au/sl/sell where I could click "Accept offer" — hopefully others have similar success. My offer expires on 14 February but the promo says 10 days from the "email" so I guess mine was "sent" on 4 Feb.
When does the promotion run?
- The promotion runs for 10 days, from the date we send you the first invitation email to participate in this offer until the end date specified in the invitation email ('Promotion Period').
What is the promotion?
- Pay no Insertion Fees or Final Value Fees for the first 3 items you list and make available for purchase during the Promotion Period (see exclusions below).
- Insertion Fees are the fees to list your item, and Final Value Fees are the selling fees charged on sale of an item, calculated as a percentage of your total sale price. The promotion does not apply to fees for optional features or upgrades. Learn more about eBay fees.
What exclusions apply?
- This offer applies to listings in Auction-style or Fixed Price format, but does not apply to listings in Classified Ad format.
- You will be entitled to participate only if you register for the offer by clicking “Activate offer” in your email invitation, accept the terms and conditions and receive confirmation from eBay that you’ve accepted the offer.
- eBay store subscribers are not eligible to participate.
- This promotion does not apply to “Excluded Categories” which include Businesses for Sale (11759), Aircrafts (63676), Boats (26429), Caravans/Motorhomes (32633), Cars (29690), Motorcycles (32073), Trucks/Commercial Vehicles (6049), Real Estate (10542), Services (316), Flights (3253), Tickets (1305), Travel (3252) and Vouchers/Gift Certificates (172008).
- The promotion only applies to listings in one category. If you add an additional category to your listings, Insertion Fees (and other applicable fees) will apply for the additional category
Plus other terms as per https://sellercentre.ebay.com.au/promo/103860
Fwiw, I've never had a sell-for-free offer so today is a happy day for me (I don't get out much). Other potential offers you might be eligible for:
* Super Sundays, Sell for $1