Seemed to work across 4 different accounts so could be worth checking.
Time to save with eBay and Nectar!
Spend 500 Nectar points or more on your next eBay shop and we’ll give you 50% of those points back!
This offer is valid for 14 days from the date received – stated within the terms and conditions of the offer email.
Please do not fret! You may have to wait a few days for your bonus points to show on your account – But no later than 28 days after the end of this promotion. Maximum 1 redemption per user Maximum 5,000 bonus points only.
Full Terms & Conditions apply.
So potentially £12.50 to spend on eBay if you exchange and spend maximum Nectar points to voucher (5000pts)