OK, so the 5 month period ended in March.

We did spend $3K+ per month on the card for 5 months, November through March.

With this months statement received the $500.00 cashback bonus.

So, between this $500, and the standard and bonus categories, we received over $800 cashback during this offer. (spend was actually just over $20K.)

$20K spend, $800 cashback = 4%

As I said in the title, best credit card bonus I have ever received (except maybe sign up bonuses... )