Information about subscribers is gold to magazine publishers. They combine the information you provide with other geographic data (education, income, etc.) and use it to help target advertisements. So, you can imagine how they felt when Apple didn’t allow subscriptions for iPad magazine apps. And, when Apple began to allow subscriptions, they placed numerous restrictions on how they worked. One restriction was that magazine publishers would not be able to get data about subscribers.
The workaround was to provide a pop-up menu dialog in iTunes to ask subscribers to allow sending the “developer” (publisher) their name, email address and zip code. If asked to guess what the take rate for that pop-up was, I would have guess somewhere in the 5 to 10% range. Forbes, however, reports that about 50% of people asked select the “Allow” button.
While this is far less than the 100% subscriber information publishers have with their paper publications, it is far better than the near 0% they probably anticipated.
Via: Surprise: 50% of iPad subscribers click “Allow” (CNN Fortune)