The popular read-later service Instapaper has been acquired by Betaworks, the startup studio that owns Digg and a number of other online brands.

Marco Arment, the creator and sole developer of the service, announced the acquisition in a blog post titled “The next generation of Instapaper“:

I’m happy to announce that I’ve sold a majority stake in Instapaper to Betaworks. 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. I will continue advising the project indefinitely, while Betaworks will take over its operations, expand its staff, and develop it further.

Instapaper

According to Arment, Instapaper has grown to such a scale that it now needs a staff of some size to maintain. But rather than putting together a staff himself, he chose to give his brainchild “a new home where it can be staffed and grown.” The decision was also fostered by Arment’s desire to work on other projects, including the iOS-exclusive publication The Magazine.

The Instapaper service was launched in January 2008 with the introduction of its bookmarking website, read-later bookmarklet, and text-only article view.

Its official iPhone app for offline reading was released half a year later and just a couple of days after the launch of the App Store. Its iPad app, on the other hand, debuted the day the iPad itself was released in April 2010. Both apps are available in one universal app currently priced at $3.99 in the App Store.

For more information on Instapaper, check out AppAdvice’s comprehensive coverage, including an App Showdown where it was pitted against rival read-later apps Read It Later (now Pocket) and Readability.