‘Tis the season for giving — and not just the items on your loved ones’ wish lists. As the flood of requests filling our inboxes and social media feeds in recent weeks illustrate, charities and nonprofits are all asking for help.  They want us to spread the holiday cheer (and secure end-of-year tax-deductions) by spending just as much on Giving Tuesday donations as we do on Black Friday and Cyber Monday purchases. Indeed, in the United States, nearly one-third of annual charitable contributions are made in December, a third of them in the last three days of the year.