I'm the CTO of a web startup, and recently I have been trying to experimentally determine if there is a consistent format to update notifications being pushed to the subscriber from a multitude of different publishers. During this testing, I used a controlled feed from YouTube to attempt to capture at least one of these update notifications. I subscribed to my YouTube account's favorites, along with one other commonly updated feed afterwards because of my preliminary results, and the subscription process went flawlessly, but I have not gotten a single POST update notification despite having explicitly changed the feed after the subscription was made (multiple times). I have checked for the update using both a coded debugging mechanism in the callback page, and by visually checking the web server access logs, but nothing has shown up.
The subscriptions are considered valid by the subscription debugger at pubsubhubbub.appspot.com, so the error is isolated to either a publisher issue, or a hub update receiving/push issue. I'm wondering if anyone knows for sure which one of these issues it is. Thank you for your time. (Same question as posed here: http://qr.ae/aZBu )
