Face it, we all end up with the occasional unwanted gift, and returning them can often be more trouble than it's worth. But Zappos is trying to fix that.

For the first 500 callers to (800) 927-7671 between 11 a.m. and 11 p.m. Eastern on Saturday, Dec. 26, the online retailer will offer a $100 Zappos gift card in exchange for any unwanted present you might have received, regardless of where it was purchased.

If you're one of the lucky 500, Zappos will send you a pre-paid return label that you can use to mail in the gift (which still needs to be in its original packaging).

Items sent to Zappos will be donated to a charity appropriate for the type of gift, company representatives said.

The "Happy Returns" idea was created by Zappos in partnership with agency Mullen Lowe. The concept was meant to highlight the retailer's commitment to customer service.

"At Zappos, we consider ourselves to be a customer service-focused company—more than just an online retailer—and as such, we're always looking for new and exciting ways to engage with and give back to our customers in an effort to build meaningful relationships," said Kristin Richmer, a member of Zappos' Awareness Marketing team. "Happy Returns is an exciting spin on our already great return policy."