Facebook isn't shy about acquiring companies for their talent or, more rarely for their technology. But this means that the products it buys are going to get shut down. The notable and so far sole exception is Instagram.
So you can probably figure out how the Spool acquisition, which was just announced, is going to go down.
Spool is, or rather was, a bookmarking service that enabled users to have their bookmarks sent to their mobile devices. There's nothing special about that in itself, but where Spool was different was in the way it served that content to mobile devices.
It converted the content, articles, videos and so on, to a format suitable for mobile devices. It's something that Flipboard or Instapaper already does.
But Spool was different in that it made copies of everything and stored it themselves, across several data center locations.
This made articles or even videos available instantly to users, in the web or mobile app and, even more importantly, made it possible to cache the content locally inside the app , for offline viewing.
The technology is, obviously, incredibly handy for a social networking company, or any site regularly used to share content.
Facebook, Twitter, Google+ and so on, provide links to the shared content, but they also include thumbnails or small snippets of the article.
In fact, both Google and Twitter were interested in the company that Facebook eventually bought and so was Dropbox, which has plenty of experience itself with storing and making available user content across platforms and around the world.
In any case, Spool is being shut down and users have already been sent an email with all of their bookmarks attached. Spool also put up a page explaining how to get the bookmarks imported either into your browser or into other bookmarking services.
It seems though that you'll be able to get the bookmarks from your email account, which is going to be a problem for those that no longer have access to it, for whatever reason.