I truly enjoy using pinboard. I even have a launchbar task for searching my links quickly. And, while I wasn't looking for social bookmarks I have to admit I really like the pinboard popular links rss feed. I suppose it's more of a niche community thing which is why I feel like they are generally of a high quality. Second only to Hacker News as my source of what's going on.
Instapaper lately has been having many messed up conversions. I use instapaper because they have a pretty clear business model. They make money from subscriptions and app sales. Pocket and Read It Later both don't have paid apps nor subscriptions. So the only other option is that you are being sold.
I'd much prefer an app I run myself with user maintained site defined scraping definitions.
I like instapaper though, it's good for what it does. Could be better though.
Pocket used to be Read it Later, a paid app. Early this year they switched to Pocket, went free, and raised $5m. So right now, afaik, they don't make any money.
The founder has said in articles/interviews that going free was the right choice for pocket, they're not looking to be acquired, and not ready to talk about their future business model/revenue streams, heres him from July when asked about their plan:
We’ve known where we are headed since last year. But like anything we do with any product or feature, we don’t release it until it’s ready. This is a new, uncharted space and we’re not prepared to release something that isn’t right.
I'll admit, I'm pretty weary of the whole thing, but willing to see where it's headed, I guess. I think if their plan was to just flog off their users data, they would have started doing it already, but it seems like they have something else (Hopefully interesting/unique) planned.