phylae

Minimizing app size is quite relevant in some circumstances. For example, when an app is being used at a live event, you could have 1000s of people downloading it at the same time over the same wifi connection. Even a small decrease in the app size will help decrease that initial bandwidth spike.

Memcached is not run (or priced by) Heroku. That is an addon provided by a 3rd party (http://www.northscale.com/).

In addition, there is absolutely nothing stopping you from running your own, separate memcached server and pointing your Heroku app there. If you host it on EC2, then you should have very low latency to Heroku.

Heroku is obviously not perfect, but this particular criticism is not valid. That said, you can point this criticism at Northscale.