I'm trying to import reviews for certain apps on the iTunes App Store via the public reviews RSS feed. Most of the time the feed returns a list of 50 reviews per page, and gives me links for up to 10 pages. But in the case of some apps, some or all of those pages have 0 reviews, and I can't tell why.
At the time of this writing, the feed for Instagram (link below) returns no reviews, despite reporting that there's 10 pages of reviews available.
https://itunes.apple.com/us/rss/customerreviews/page=1/id=389801252/sortBy=mostrecent/xml
Even more confusing, I noticed last night that page 2 had 50 reviews but none of the other pages had any. This morning, page 2 is empty again.
If I remove the sortBy=mostrecent
portion of the URL above, I actually do get 50 results back, but none of the other pages have any results.
Finally, it appears as if the JSON version of this page (link below) actually returns results better than the XML version. Unfortunately, the JSON version leaves off the date of the review in the data so I can't use it.
https://itunes.apple.com/us/rss/customerreviews/page=1/id=389801252/sortBy=mostrecent/json
Can anyone explain this? Is Apple's XML feed API just extremely unreliable? Am I forming a bad URL?