diff --git a/README.md b/README.md
index 37e5991..fe2a013 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,8 @@ These include:
   [`ko`](https://github.com/google/ko).
 * [`buildpack.kontain.me`](./cmd/buildpack), which builds a GitHub repo using [CNCF
   Buildpacks](https://buildpacks.io).
+* [`wait.kontain.me`](./cmd/wait), which enqueues a background task to serve a
+  random image after some amount of time.
 
 This repo also serves [`viz.kontain.me`](./cmd/viz), which visualizes shared
 image layers using [Graphviz](https://graphviz.org/).
diff --git a/cmd/wait/README.md b/cmd/wait/README.md
index 82ed579..e90dc85 100644
--- a/cmd/wait/README.md
+++ b/cmd/wait/README.md
@@ -29,3 +29,13 @@ This screencast requests an image that should exist in five seconds, then waits
 to see it appear and checks that it's valid.
 
 [![asciicast](https://asciinema.org/a/JUiiq33BaGF3NGx10PP6uvETf.svg)](https://asciinema.org/a/JUiiq33BaGF3NGx10PP6uvETf)
+
+## Why?
+
+This demonstrates being able to asynchronously produce an image, rather than
+blocking the initial pull HTTP request until the image is available.
+
+A container orchestrator like Kubernetes would pull this image and report
+`ImagePullBackoff` until the image was finally served, at which point it would
+pull and run it. In the meantime, the registry could be building or mirroring
+or modifying the image in the background.