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.