An opaque black box called App Store needs to become more transparent so we can figure out why our sales pick up or fall down. Without this, without the ability to measure and distinguish the sources of income, spending money on marketing is mostly flailing around hoping it sticks somewhere. No small-dev shop can afford that.
As someone who works with small iOS developers to promote their apps, I would absolutely love something for them to track how much traffic marketing campaigns throws their way.
Today we have hacks like click trackers, but nothing to show how often sales convert from a particular source. Advertisers who do direct sales happily come back because they see how effective an ad campaign can be.
Over the past year, I have seen smaller iOS developers start to shy away from ad networks like The Syndicate and Fusion Ads – and this is the key reason why. They simply have no idea if it will help their sales, and $1000+ is just too much money to spend on that risk.