I got an interesting AmEx offer on my Business Platinum, just in time for tax season:
Get 17,500 additional Membership RewardsŪ points by using your enrolled eligible Business Card to spend a minimum of $69,000+ in one or more qualifying purchases. Once you add the offer to your eligible card, you will have 90 days to spend $69,000+ or more. See terms.
I was able to get 69k * 3 worth of purchases approved in advance and went ahead and charged for IRS payments yesterday. Here's hoping that the 17.5k point bonuses come in. Given that these are eligible for 1.5x points, each charge of $70k yields 122.5k points. At prevailing CC fee rates of 1.85%, it's not a smashing deal but it seems like a good idea for businesses with several hundred thousands of tax liability or more.