[webpayments] Transition and Adoption (#94)

Consideration needs to be given to the user experience during transition to the WebPayments API.

During this period there will be the following issues;

1. Merchants wanting to accept payments methods where no payment application exists
2. Customers having no payment applications registered

To ease adoptions, these important situations need considering by the group.

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/webpayments/issues/94