Say hello to the Bandwidth Alliance, a new group led by Cloudflare that promises to reduce the price of bandwidth for many cloud customers. The overall idea here is that customers who use both Cloudflare, which is turning eight years old this week, and a cloud provider that’s part of this alliance will get a significant discount on their egress traffic or won’t have to pay for it at all.

The alliance is open, and others may join still, but right now it includes virtually every major and minor cloud provider you’ve ever heard of — with one exception. Current members include Automattic, Backblaze, Digital Ocean, DreamHost, IBM Cloud, Linode, Google, Google Cloud, Microsoft Azure, Packet, Scaleway and Vapor. Some of these will now offer free egress traffic to mutual customers with Cloudflare, while others will offer at least a 75 percent discount.

That’s quite the alliance, but as Cloudflare CEO and co-founder Matthew Prince told me, once the first member joined, the rest of the pieces fell into place quickly. Surely it also helped that both Google and Microsoft have invested in Cloudflare.

Why would these businesses choose to do away with what’s a minor but high-margin business, though? “The argument that we made to them was a pretty simple argument: it makes sense for you to charge for transit when you are actually paying for it,” Prince said. Most of the time, though, those costs are very minor and Cloudflare, thanks to his massive number of global peering locations, can ingest the traffic directly from the cloud provider with no middlemen involved.

The first company Cloudflare partnered with was Google, thanks to that company’s CDN Interconnect program, which launched in 2015. Cloudflare was one of the initial partners in the program, though as Prince noted, there was still a lot to learn for all parties involved, especially because traffic was sometimes routed in very unpredictable ways that circumvented the cost savings mechanisms. Cloudflare learned from this, though, and is now using its own Argo technology to intelligently route traffic.

As Prince noted, though, one thing that turned out to be harder than anticipated was ensuring that the cloud vendors would know that one of their customers is a mutual customer. Some have that instrumentation in place, while Cloudflare needs to pass a special header to them so they can know where their traffic is coming from.

Prince also argued that this will make it easier for many companies to use multiple cloud providers without having to pay extremely high bandwidth cost. While Cloudflare’s early focus was very much on web traffic, Prince said that more than half is now API-based traffic, and that’s exactly the kind of user who will likely save quite a bit of money thanks to this.

The one company that’s not part of this alliance, of course, is Amazon with its AWS platform. Prince said that Cloudflare has talked to them, though, and the group is open to all cloud and CDN providers.