[Update] I originally had this wrong. Based on reader feedback, this perk has not been canceled; it was simply changed. The extra 10% is now applied directly when the cashback posts. I double-checked, and that is indeed how it works. The 10% is added directly into the cashback amount, so 3.3% is still pretty solid:

BofA has a credit card that is especially good for beginners to keep long term, commonly nicknamed the 123 card: BofA Cash Rewards credit card. This card also has another perk: if you redeem cashback rewards, including the sign-up bonus, into a BofA deposit account, you get an extra 10% bonus.

In January 2019, BofA removed the 10% benefit for new users, but existing cardholders still kept it. That meant you could pick a cat and earn 3.3% cashback. However, recently BofA seemed to have removed this benefit entirely. I redeemed some rewards this month and found that there was no separate 10% bonus at all, and the redemption terms no longer mentioned this perk either. R.I.P

This 10% benefit is real, and it is easy to forget about. You can still find some information about it in the Terms, for example:

Also, BofA's discontinued free-money favorite, the BBR, still keeps its perk of automatically redeeming into a BofA account with an extra $5 bonus each time, amazingly enough. That's an easy $30 every quarter, which is still quite nice. Hopefully BofA keeps this benefit around.