There are some significant high volume cases. We work with companies doing billions of Lambda invocations per month and realising large cost saving benefits. Lambda itself is usually the smallest part of the bill as one of the advantages of building serverless applications is you shift the responsibility of certain execution to specially designed managed services as opposed to code consuming CPU cycles; for example API Gateway takes over routing, S3 takes over file system calls, etc. A large portion of savings organisations see though is in time to production, as well as the overhead of managing servers and container clusters which is a lot more costly than you might think. Especially in the environment we are in now where qualified Dev Ops talent is hard to come by and at a premium. Sure, a developer can take some time to try and learn how to put together some infrastructure, but that's time taken away from adding direct value to business needs and not to mention the fall out when things go pear shaped later because it turns out a few hours Googling doesn't turn someone into a DevOps expert.