>
There's starting to be a pushback against developers releasing games for free and monetising through IAPIf a free app is a demo and IAP is a one-time upgrade to the full version, then it's reasonable and perfectly acceptable. This is, arguably, what the IAP were actually designed for - a nextgen support for try-then-buy software.
The pushback is typically aimed at tacky milking practices - "a satchel of coins for $5.99, a pot of gold for $15.99, etc". You either release a limited, but self-contained playable demo, or a fully functional game. Anything that falls into a stretch between these two feels like a sleazy bait-n-switch kind of deal, hence the pushback.