It's why I paid for pinboard but then left it for Kippt. It's how I judge any service that I'm checking out and especially how I read information online. There are probably less than 5 sites that I actually read straight from the site. The rest go to Readability to either read now or saved to read later. Tapbots integrating that into their Twitter app was amazing for me.
This is huge for people that spend lots of time in front of screens. The minimum requirement is usability but aesthetics are used for driving enthusiasm.