Right, because the Kindle refreshes when you turn the page or use the menus. That would be a refresh every 30 seconds or so while you are using it.
If you are using it as a primary display on a phone showing dynamic content, you are going to be refreshing it as quickly as you can the entire time you are using it. I think modern low end panels can maintain about 7 fps or a refresh every 0.15 seconds. That's a two order of magnitude difference.
I have never seen or heard of an epaper display wearing out but I don't know of anyone who has tested. I'm tempted to grab one of my spare screens and just hook it up to an arduino to constantly refresh it.
The e-ink corporation has some lifespan information in their datasheets. For example, their Pearl screen is listed as having a life of 10 million refreshes. If you are updating more than once per second when in use, you will use that up in a year or two.
