Could be selected accounts so check your emails or at the bottom of 'My ebay' page. On 1 of my account's it lasts for 2 days £1 and on another it's 3 days £3. Up to 100 listings.
My previous offer of 75% off ended so didn't relist waiting for another and this is a really good 1.
Q: Did the offer work after clicking accept ?
A: look on the bottom of 'My ebay' page ('Promotional offers') and it should be there as 'Active'