Incentivized download offers ask you to install an app in exchange for some type of virtual goods or currency. For example, "Install one of these apps, and you’ll get ten free gold coins!" This type of thing has been happening for some time; however, only recently started to reject applications because of it. It’s thought that perhaps Apple is upset that developers are using the incentivized downloads to push their app into the top 10 lists.
TapJoy writes, "As you may have heard, a number of applications submitted for update have very recently been rejected from the Apple App Store based on the fact that they were running incentivized app installs within their apps. This is something new from Apple and we, along with every partner we’ve talked to, were unaware of this prior to these notices of rejection. Like many application developers, we have reached out directly to Apple and look forward to clarification.
To be clear, there is no new Apple policy that we are aware of. It seems there may be a new interpretation of the existing 3.10 clause, which is a bit surprising, as Tapjoy, AdMob, iAd, Flurry, W3i and others all power various forms of app install advertising. Many of the brands that promote their apps via Tapjoy also do the same on other major ad networks across the mobile advertiser ecosystem, and all of the apps we promote on are Apple-approved."
3.10 reads: Developers who attempt to manipulate or cheat the user reviews or chart ranking in the App Store with fake or paid reviews, or any other inappropriate methods will be removed from the iOS Developer Program
Apple Cracks Down on Incentivized App Downloads