This used to work for me but is now not working anymore and I can't figure out why. I have in-app purchase setup in my app. I confirmed that I have a correct set of product identifiers, matched by corresponding in-app purchase items in itunesconnect. The call goes out to Apple view [productRequest start], but I never get a response back, despite setting the delegate to myself. What am I missing?

NSLog(@"productIdentifiersSet: %@", productIdentifiersSet);
if ([productIdentifiersSet count]) {
    SKProductsRequest *productRequest = [[SKProductsRequest alloc] initWithProductIdentifiers:productIdentifiersSet];
    [productRequest setDelegate:self];
    [productRequest start];
}

………

- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response {
   <never called>
}

- (void)requestDidFinish:(SKRequest *)request {
    <never called>
}

- (void)request:(SKRequest *)request didFailWithError:(NSError *)error {
    <never called>
}