I have enabled inapp purchases in my chrome extension. I have been getting reports that people that don't have google wallet account, and people trying to add a new card are not able to make a purchase.
Here is an image of what happens:
I can't tell if this caused by a issue on my side, or if google wallet is not working. I have tried to reach out to google chrome support, but they told me for my users to to contact them about adding cards. This makes it really hard for new customers to acquire products.
This is in fact a bug in the in-app payments support in chrome. I filed http://crbug.com/485252 to track this issue, and am working on a fix. In the mean time customers should be able to add payment instruments by going to https://wallet.google.com/ directly.