Amazon (AMZN  ) customers will soon have another option besides the standard credit card to make their purchases. Affirm (AFRM  ), a buy now pay later provider, is teaming up with the biggest name in online retail to offer installment payments on select purchases over $50.

Contingent upon their approval, the new option will allow customers to spread out payments over time, without any hidden fees or late charges, according to a release from both companies. Currently, only select Amazon customers can "buy now and pay later," but the functionality is expected to roll out more broadly in the coming months.

"By partnering with Amazon we're bringing the transparency, predictability and affordability that Affirm provides today to the millions of people who shop on in the U.S.," said Eric Morse, Senior Vice President of Sales at Affirm, in a statement. "Offering Affirm's alternative to credit cards also delivers more of the payment choice and flexibility consumers on Amazon want."

News of the partnership sent shares of Affirm soaring by more than 30%. At the time of this writing, Affirm currently trades at $96, whereas before the announcement, it traded at $67.

Nor is Amazon Affirm's only high-profile partner. Affirm currently has more than 12,000 merchants in its network, the most prominent being Walmart (WMT  ) and Peloton (PTON  ), with the latter accounting for as much as 30% of Affirms revenues in the first quarter, according to data from FT Partners.

Investors had worried about Affirm's prospects as rivals are pushing hard into the space. Square (SQ  ) recently bought out Afterpay, giving BNPL options to the millions of merchants and Cash App users within its network. Meanwhile, Bloomberg reports that Apple (AAPL  ) is working with Goldman Sachs (GS  ) on its own BNPL service in conjunction with Apple Pay.

However, Amazon moved $500 billion in gross receipts last year alone; if Affirm has a hand in even a tiny fraction of those transactions, it would be a considerable boost to its bottom line.

As a result, the Street has taken notice. Analysts at Barclays and Morgan Stanley have raised their price targets on Affirm from $85 to $115 and $73 to $120, respectively, with both groups calling the stock "overweight."

BNPL has exploded lately as consumers, particularly younger ones, grow wary of taking on debt to make larger purchases, especially in light of the pandemic. A survey by Mizuho Securities of 200 Amazon shoppers found that half would likely use Affirm to make a purchase. Mizuho analyst Dan Dolev contends the deal could drive 20% to 30% incremental gains for Affirm's gross merchandise volume.

"Partnering with the #1 U.S. e-commerce retailer could launch AFRM into higher orbit, making the fear of competition from Apple Pay earlier this summer seem like a long-forgotten bad dream," he wrote.