Reader's "RSS feeds" had long been a popular way to stay updated on subjects of interest, but users are increasingly turning to social media such as Facebook and Twitter instead.
"Most content now is tied to some dedicated platform or other," said Silicon Valley analyst Rob Enderle of Enderle Group.
"Getting rid of this service shows good governance by Google... In a world of limited resources, this service just wasn't making the grade."
Diehard Reader fans were outraged by Google's move.
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"This is about us using your product because we love it, because it makes our lives better, and because we trust you not to nuke it," read the first petition, started by a New York City man. "So, please don't destroy that trust."
Google was not deterred, and visitors to Reader today were greeted with a message reminding them that the service would cease to exist at the end of the day.