I know that traditionally Instapaper basically required you to load the page at least once first so you'd get all the ads then. But since then there's APIs that

I know that traditionally Instapaper basically required you to load the page at least once first so you'd get all the ads then. But since then there's APIs that bookmark directly to it. My guess is that it isn't used enough for Web sites to bother. I view it as a specialized browser view, although the cloud bookmarking doesn't fit with that. I use Safari's reading view on pages all the time as they're too visually busy for the screen on my iPhone 5.