Tesla is giving away a free car to owners who get their friends to buy a Tesla

• Tesla is dangling the prospect of a free Model 3 in front of its loyal fans.
• Tesla owners who get a friend to buy a Tesla before the end of the month could win a free car.

Want a free Tesla? Just get a friend to buy one before the end of the month.

That's the promotion Elon Musk's car company is offering its fans in an apparent effort to boost sales as the third quarter comes to a close at the end of September.

Tesla runs a loyalty program whereby owners get a unique referral code they can share with friends. When someone buys their first Tesla with that code, both the buyer and the referrer get perks of some kind. Referrers can rack up credits this way, which they can spend on things like software upgrades and free Supercharger visits.

Tesla on Tuesday introduced a new referral benefit for US customers. Owners who get a friend to buy and take delivery of a new Tesla between September 19 and September 30 will be automatically entered for a chance to win a Model 3 Performance, which costs $53,240.

Owners can also buy entries in the sweepstakes for 1,000 credits a pop.

Lately, Tesla has run limited-time promotions to juice sales as a quarter comes to a close. In the past, it's discounted vehicle prices and offered free Supercharging to buyers who act quickly. Musk has also been known to send company-wide emails during the end-of-quarter push urging employees to put the pedal to the metal.

Tesla significantly pared back the referral program in recent years after saying it was too expensive to the company. This year, it revamped and expanded the program as it looks to sell more cars at lower profit margins.

Credits can also buy Tesla fans a factory tour or an entry to win a futuristic Cybertruck pickup.