Yev from Backblaze -> B2 can be a bit cheaper because our service works a bit differently from S3. For example, uploading files doesn't require expensive load balancers in our data center. Instead, we require the dev to make 2 API calls to upload a file, instead of 1 in S3. The downside - our API isn't S3 compatible. However, the upside is pretty compelling - we pass the savings on and give you considerably cheaper storage.

Folks from the Beta have said that using our APIs they were able to integrate their apps to B2 from S3 relatively quickly. That said we're still early, so it may be that we develop some more compatible APIs in the future.

Some of the cost-efficiencies are achieved by architecting the software somewhat differently. The most important one is that the user requests and upload URL and then posts to that, which saves us from needing big, expensive load balancers.

At the same time, we're working with partners who will abstract our B2 API to make it akin to the S3 API.

Gleb from Backblaze