I just received confirmation from HBSC that our $25 cash back redemption request has been received, and our check will arrive within 15 business days. Not a big sum of money, but the only thing I had to do to earn it was charge my business trip expenses to my HBSC rewards Mastercard (which my company immediately reimburses me for).
My wife and I also have a Citi Dividend Platinum Select MasterCard that we use for most of our household expenses. The card is paid off monthly and earns us up to 5% cash back. In fact, we should be able to request a $50 reward from the Citi MasterCard next month. Easy money.