Just logged into my ebay account and saw it on home page.
And also in message section with subject "A huge THANKS—earn 6% eBay Bucks."
You must activate the offer to get eBay bucks
Who’s eligible?
Only registered eBay Bucks participants who receive the offer from eBay in My Messages and pay for the item with PayPal are eligible. Sorry, no forwarding—the offer is not transferable.
6% in eBay Bucks on every qualifying item
Promotion details
The Promotion starts at 5AM PT on June 28, 2016, and ends at 11:59PM PT on June 29, 2016. Extra eBay Bucks can only be earned on every single item purchased that meets the minimum purchase requirement specified in the offer. Valid on multiple qualifying purchases made within the promotion time period. In order to qualify for the offer, you must click the email to activate.