except read it later and instapaper are useful on more browsers than just safari.
Instapaper's API has insane support across 3rd party apps and the web.
I kinda agree with the person who suggested this might help Instapaper (even if it syncs across Mac and iOS).
It will introduce folks to having the ability to sync web articles across multiple devices, and the added functionality in instapaper (non mac/ios, great integration into 3rd party apps and websites) might swing many to shell out the few dollars to get Instapaper instead.