How do returns work in mobile app stores vs. regular stores?

I was wondering if anyone was familiar with mobile app return policies and how they affect cash flow. When Apple/Google sends a monthly check for an app, does that already discount returns and chargebacks? Would I potentially need to hold a reserve?

(Also, if I take CC myself, would I typically use a reserve to account for returns?)

For the Apple App Store at least:

How can I identify refunds? Why there are refunds on my reports? What
is Apple’s refund policy?

In the report the customer price and the
units will be negative (i.e. proceeded by “-“). Our refund policy is
“All Sales are ?nal”. We will provide a refund if in our opinion the
customer experience was unsatisfactory (generally app quality
issues). One thing you may want to monitor on your reports is the rate
of refunds for the apps that are being refunded since it is an
indication of quality issues with your apps that may be resolved by
issuing a software update.

http://www.apple.com/itunesnews/docs/AppStoreReportingInstructions.pdf For Android there are some guidelines here: http://www.android.com/us/developer-distribution-agreement.html Digging through that, I think the policy is 48 hour returns, but I'm not completely confident in said answer.