What are some ideas for tracking of up-sell from Lite to Full applications? The best idea that I got is to make the Lite and Full apps do a quick phone-home with a hashed UUID (something that stays the same between Apps) -> but doesn't this approach have to be cleared with the user (or face Apple's lethal rejection squad)? I'm not sure if this is immediately available off iTunes Connect or not (I don't think it is), but that would be the best spot, obviously, to be tracking this information. Any suggestions welcome.
There are a lot of apps that retrieve the device ID for their own statistics. You shouldn't run into any problems implementing the retrieval. At that point you can see which devices are upgrading to full after they bought lite, how long after they bought lite did they decided to buy full, etc. If someone already has such a system, they should post their results.
I've also seen lite versions use bit.ly links to the full version. This doesn't track actual sales, but does track clicks easily.
