The main thing Kafka is great at is scaling out via partitions with it's natural stickyness, while maintaining excellent ordering guarantees. This means it's re

The main thing Kafka is great at is scaling out via partitions with it's natural stickyness, while maintaining excellent ordering guarantees. This means it's really easy to create a load of reliable in-memory processing where each thread processes a single partition of data. When scaling out on a standard message queue you generally have greedy consumers which means you can't assume stickyness, or have to create your own partitioning structures. It makes it great for realtime apps... If there were cheaper alternatives I think people would use them but it does definitely have powerful benefits.