Marketplace
I know this was posted only recently, but that's expired already and I received another email from eBay today. It's not quite two weeks this time around, when I accepted the offer it told me the promotion is good between 17-28 August.
This is targeted, so check your seller accounts if you're eligible. Usually it will show up at the bottom of the All Selling page in the Seller summary, but it should also appear in the internal eBay messaging Inbox as well.
received this 2 days ago on all 5 of my accounts :)