Google Checkout,
- Not present at all in a number of countries
- Impossible to sell from an even higher number of countries
- No customer support at all
Paypal
+ present virtually everywhere
- customer service generally considered frustrating, becomes terrible when dealing with their fraud detection
iOS AppStore
+ present in more than a hundred countries (though some parts e.g. iAd may not be available everywhere)
± customer service generally regarded as good, except when dealing with the approval process (and even that area shows progress)
Hi, may we help? :) We also do have forums that are actively monitored.
Also if anyone is interested, checkout is present in these countries: http://goo.gl/I49QQ
Coincidentally, I've never had such a problem with Paypal. (My gripes with them generally revolve around the glacially slow history search.)
I got my account auto locked when an apartment move, sales spike (Valentine's day), and large withdraw all hit at once this week. It took one call and two minutes on thhe phone to resolve. "Sorry Mr. McKenzie, we just saw an unknown individual try moving a lot of money in and out of your account and wanted to make sure it was you. You're good to go."
