Capital One LifeMiles 15% bonus: Modest, but unlocks Europe biz at 69K with no surcharges.

Bank of America cardholders can score a $175 statement credit by spending $1,500 within 90 days through the close-card flow in the app or online chat. That's an 11.67% return before normal earnings, which on a Customized Cash card with the 3% online category pushes it to 14.67%. BofA appears to allow one retention offer per cardholder at a time, so target your most valuable card first. The process gives clear warnings before closing, so there's low risk of accidental cancellation.

Bank of America's 100K Flying Blue offer on the Air France/KLM card requires $7,500 spend in 180 days with an $89 annual fee. The 100 XP lands you Flying Blue Silver status, which includes priority check-in, boarding, and an extra checked bag on SkyTeam. That alone makes the card worth considering if you lack SkyTeam status, especially given the 5,000 anniversary points and mileage expiration protection. The normal card is not worth a 5/24 slot, but this bonus is sizeable enough to reconsider, particularly for those over 5/24 or with a specific Flying Blue redemption in mind.