Are these sweetened (>2%) eBay bucks deals available to all participants, or is it a targeted marketing to certain individuals.
Although your US BANK flex perk card may be a wonderful exception (I'll have to look into it), I've unfortunately had bad experiences with travel perk programs (if it wasn't blackout dates, it was some other deceptive restriction that made me wonder why I signed up).
The sweetened deals are invitation only and unique redemption code is issued for your ebay account. To me it seems somewhat random when I get these, but every account I have does get them each quarter at different times in the quarter. When the 10% days occur I often have no limit on how many items I can buy, but hit the $500 quarterly cap quickly that day because there are plenty of items I would buy at 10% discount.
The flex perk card you don't earn miles, but rather points, you can redeem points for 1.5% cash back or use the points for travel on any airline on any day which gives you an effective rate of 3%. The only requirement is you must book your travel through Travelocity.com web site which has the same prices as expedia.com or airline sites. If a ticket on delta.com cost $395, then it will cost you 20,000 points on Travelocity and you will get $25 to spend on the plane for food, drinks and internet per ticket. The only catch is you must redeem points in 10,000 increments and each 10,000 buys you $200 worth of tickets, so if the price of the ticket is 199.99 it costs 10,000 points (thus earning 3% effective rate), but if it is $200.00 it costs you 20,000 points (thus earning 1.5%), I use it only for tickets that cost within 15% of $200 increment or use it for expensive tickets to China which may be $1,125 or 60,000 points.
There is no better card out there if you like to travel and you spend a lot on your credit card.
Arif