Hi Rob, I responded to a similar review you left for us on Site Jabber, but in case you didn't see it, I've posted it here as well. While we wish that all merchants would offer flat cash back rates, many of them have very specific terms and exclusions based on what you purchase. These terms are determined completely by the merchant. To check for terms and exclusions, all you need to do is click the 'i' icon on the Shop Now button. Any terms that we know about will be listed there. I've pasted below the terms that AirBnb has listed on their store page.

'10% standard cash back for hosts only, on booked listing amount when guest checks in. Hosts must create listing after clicking through Giving Assistant.'

If you have further questions or concerns, please send us an email at help@givingassistant.org.