Marco Arment sells Instapaper to Digg owner Betaworks (which promises not to kill it)

Since debuting in 2008, Marco Arment’s Instapaper has become the heart of our new read-it-later online culture. Whereas years ago most of us saved interesting articles via an unwieldy string of browser tabs, Instapaper’s arrival meant we could easily save links and revisit them later. It was a godsend.

But Instapaper is all grown up now, and Arment is letting his baby go: The Instapaper founder announced today that he’s selling Instapaper — or at least most of it — to startup studio Betaworks, which also owns Digg, bit.ly, and Chartbeat.

Arment, who will act as an adviser to Instapaper indefinitely, said he sold the service because it had gotten too big for him to manage alone. “To really shine, it needs a full-time staff of at least a few people,” he writes on his blog.

Fortunately for hardcore Instapaper users, the Betaworks deal is all about keeping the service around for as long as possible.

“We’ve structured the deal with Instapaper’s health and longevity as the top priority, with incentives to keep it going well into the future,” Arment writes.

As for Betaworks, the Instapaper buy comes not long after it bought social news site Digg, which recently announced that it’s working on a replacement for the soon-dead Google Reader. Clearly, CEO John Borthwick and company have a lot of big plans for the future of online content.

“With Betaworks’ drive and resources now behind it, I’m confident that Instapaper has a very bright future. I’m looking forward to seeing what they can do,” Arment writes.