the main thing i hate about the android market is that as developer, i just wish they would give youthe OPTION on your refunding policy.
i know they changed it to 15 mins from 24 hours, which helps devs, but i still think they should give the dev some kind of option which even includes no refunds.
i have more 'cancels' for my app on the market than actual sales now a days, and i'm pretty sure it is because my app is just a guide for a video game with tons of info. with the 15 min return policy, you can purchase it, look up the info you want, then just get your money back.
if i could, i'd put no refunds on my app. it is .99 cents which is hardly any cash to spend on something you will use every now and then and i spent a lot of time making it, and the fact it is a guide makes it so you can just look stuff up and cancel the order because you found what you needed.
i noticed this trend after my initial surge of sales where i'd hardly have any returns. it was when the daily sales of like 3-5 or so started to come in with just as many cancels that i realized people were probably doing this. i can't say for 100% this is the case, but it seems very likely IMO.