From Dec until Mar both my wife and I applied for 5 cards each. In March we decided to refinance and the bank asked why so many new credit cards. I said it was all for the miles and they had no problem with it. I even applied for two additional cards in the middle of the process. I have excellent credit and very low debt to income so that's why they said it was no issue.
What was the Amazon Payment issue? I'm curious about that too.