I have in the past warned people against using FeedBurner to distribute their RSS feeds, and all the more so after it was acquired by Google. Now that Google is engaged in a quest to eliminate RSS, the future of FeedBurner is in question. And now people's FeedBurner feeds have started going dead for no reason. And on July 26 Google announced then that the Twitter account @FeedBurner was being closed, as was the FeedBurner Blog. Personally I think they're pushing people to post feeds to Google+, which has no RSS in or out - it's a closed environment. If you're willing to pay for analytics, then you should switch to something like FeedBlitz right now. But more importantly, no matter what you do, you should host your RSS feed on your own URL so you can switch providers without losing all your readers.