In an open letter to Amazon CEO Jeff Bezos this week, Allbirds’ Joey Zwillinger and Tim Brown asked him to go one step further than copying the idea for the brand’s infamous shoes. Arguably, the retail giant has already done that – headlines were made recently when shoes appeared on Amazon that looked remarkably similar to Allbirds’ bestseller, the Runner. But now, instead of suing, Zwillinger has proposed that if Amazon is going to make similar shoes, it asks that it use its open-source, sustainable technologies, too.

“We recently saw a product Amazon makes and sells that is strikingly similar to our Wool Runner,” the letter by Zwillinger begins.

“We are flattered at the similarities that your private label shoe shares with ours, but hoped the commonalities would include these environmentally-friendly materials as well.

“Alas, we’re here to help. As we’ve done with over 100 other brands who were interested in implementing our renewable materials into their products, including direct competitors, we want to give you the components that would make this shoe not just look like ours, but also match our approach to sustainability.”

Judging by the price point on Amazon’s shoes, this isn’t the case. Its considerably cheaper 206 Collective shoes were priced at $70, compared to Allbirds $160 shoes. The materials are unlike Allbirds’, which are made from sustainable materials like Merino wool, renewable caster bean oil, tree fibres and sugarcane.

As well as this, according to Zwillinger, Amazon has been even cheekier than just copying a design. He says the company used its resources to bid on keywords and search terms in search engines and then replaced inquiries related to ‘Allbirds’ with Amazon’s offering.

Amazon isn’t embarrassed of its efforts, either. In a statement to Business Insider, a spokesperson said, “Offering products inspired by the trends to which customers are responding is a common practice across the retail industry. 206 Collective’s wool blend sneakers don’t infringe on Allbirds’ design. This aesthetic isn’t limited to Allbirds, and similar products are also offered by several other brands.” 

The natural reaction by most companies in this situation would be to sue. However, there’s a catch – if companies like Allbirds wanted to sue Amazon, they may be in trouble. Amazon is a huge, cash-rich company that can take on the smaller ones with ease and out-endure them in court.

However, Zwillinger has taken a different approach. Allbirds has worked hard to make most aspects of their footwear sustainable, including creating a foam called SweetFoam to be used on the bottom of sneakers made from a sugarcane waste stream. More often than not, this foam is typically derived from petroleum.

Zwillinger has offered Amazon use of the sustainable innovation Allbirds came up with, as it will make an even bigger impact on the world than what his brand is doing.

“If you replaced the oil-based products in your supply chain with this natural substitute (not just for one product, but all of them), we could jointly make a major dent in the fight against climate change. With the help of your immense scale, the cost of this material will come down for all users of this material, allowing for even broader adoption,” he says.

The patent to SweetFoam has been made public, which open-sources the technology to the rest of the world, including businesses like Amazon.

“Customers value companies that are mindful of the planet and profits, and we believe the most powerful businesses in the world, such as Amazon, should lead on these issues, and will be rewarded for doing so,” Zwillinger says.

Whether Amazon will take them up on the offer is yet to be seen. However, Allbirds is betting on its reputation as being the front runner in sustainable footwear and the loyalty of their fans – as ultimately, if consumers value a brand, they won’t buy knock-offs.