Tesla Motors has rebooted its successful referral program, which offers big prizes to turn its already devoted ownership base into a fervent band of salespeople. This time around, the format has been changed, and the focus isn’t just about boosting sales of its all-electric Model S. It aims to encourage installations of home EV chargers too.

Tesla’s latest referral program began Tuesday and runs through April 15. Customers who purchase a Model S through a unique referral link and take delivery by April 15 will receive a $1,200 credit towards the cost of installing a home EV charger applied to the purchase price. The credit should cover the bulk of the cost to install home charging.

The company recommends installing a NEMA 14-50 outlet or a Tesla Wall Connector, a hard-wired charging station, to prepare for home charging. The average NEMA 14-50 installation is between $1,000 and $2,000, according to Tesla. The Wall Connector costs $750.

Tesla owners are allowed up to three referrals. Each qualified referral gives the referrer a chance to win in a drawing. One referrer will win a Ludicrous P90D Model X and an all-expense trip for two to tour Tesla CEO Elon Musk’s other company, SpaceX in Hawthorne, Calif. Five referrers will win a tour for two of SpaceX, including travel and accommodations.

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This is a more inclusive anyone-can-win-if-they-play type approach than the last two referral programs. In the previous two, prizes were issued to those who had the most referrals. The competitive format led one top referrer to convince 188 people to buy Model S sedans, PC Magazine reported at the time. That’s about $16 million in sales. The referrer, known as Wei70644, received a P90D Model S, a Powerwall home battery pack, and an invite to the opening of Tesla’s Gigafactory, the massive lithium-ion battery factory being built outside of Reno, Nevada.

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The first referral program, which ended in October 2015, issued $1,000 credits to the referrer and buyer. The second referral program dialed back the incentives and only offered the buyer a $1,000 discount on their new car.

As always, there’s a catch to these types of sales incentives programs. In this case, it’s timing. It takes about six weeks from order to delivery for a Model S, according to a Tesla spokeswoman. To qualify, buyers must take delivery by April 15. That means most purchases will have to occur by March 5.