Taking this decision is very difficult to me. I'm still using Printful everyday, but I can't justify the the time I'm investing in it anymore. Hosting a service like Printful requires very expensive servers and supporting them just for the cost of the application has been proven almost impossible to me.
Another players in the same space are either backed by VC capital and providing their aplications for free (Flipboard) or require monthly subscriptions to access their services (Readability). This makes it very difficult to compete in this space for an independent developer without external funding like me.
Also, keep in mind that Printful had to parse and process a very high number of pages everyday (a lot of users had more than 1000 feeds), since all the articles where preprocessed on the server side to provide a better user experience. Other services, like Read It Later, only process the articles you add to your reading list, which dramatically brings down the server costs.
On the other hand, everyday I see more newspapers adding paywalls to their sites, and I think the trend will only increase in the coming months and years. Eventually, they'll make RSS lose most of its value.
For all these reasons, I had no choice but pulling the plug as of November 2nd.
Alberto