Through its Emerald Club, National Car Rental has launched its annual “One Two Free” promotion. This promotion offers registered Emerald Club members one free rental day for every two qualifying rentals of a midsize or larger vehicle (for two or more consecutive days).

According to Enterprise Holdings, members can earn up to 50 free rental days by participating in the promotion, which begins today and includes an earning period through Jan. 31, 2014.

With the introduction of a points-based system, National has enhanced this year’s “One Two Free” promotion by allowing Emerald Club members to earn bonus points for non-rental activities.

In addition to the points members earn for qualifying rentals (each is worth 300 points, with a free day awarded once a member earns 600 points), other opportunities to earn bonus points include referring up to 10 friends to join the Emerald Club and the promotion (300 points per referred individual upon completion of a rental), downloading National’s new mobile app (one-time bonus of 25 points) and using Facebook to connect on National’s “One Two Free” promotion site (50 points).

And if a referred friend becomes an Emerald Club member, registers for the promotion and completes a qualifying rental by Jan. 31, 2014, participating members receive 300 bonus points, says Enterprise.

“For more than a decade, ‘One Two Free’ has been a very popular promotion with our loyal Emerald Club members,” said Rob Connors, assistant vice president of brand marketing for National. “This year we’re offering them even more reward-earning opportunities outside of the rental process.”

Visit www.emeraldclub.com to join National’s Emerald Club and take part in the “One Two Free” promotion.