In what cases will bitcoin be better for small transactions online than a credit card? I'm at a loss for examples.
To pay online right now, you have to decide: 1) do I trust this vendor 2) do I want to fill out this form with all my info
Generally this (plus transaction fees) only make sense for transactions above $10.
The vendor responds by trying to build a relationship with you- by building brand trust and by pushing you toward an ongoing relationship (recurring payments, creating an account etc). This is why "cards on file" is considered a major business asset online.
As a result, any online service that doesn't make the cut is forced to resort to an advertising based business model.
You can see this with the tipping culture on Reddit. It's helped Dogecoin really take off, because it's pretty trivial to send a small, casual payment to someone.